"What is the USN helium-oxygen (HeO2) decompression table?"

"Table 12-4 of the U.S. Navy Diving Manual Revision 7 is the Surface-Supplied Helium-Oxygen Decompression Table. It covers depths from 60 to over 380 FSW with a descent rate of 75 FPM and ascent rate of 30 FPM. Decompression uses the bottom helium-oxygen mix at 50 FSW and deeper, switches to 50% O2 at 40 FSW, and uses 100% O2 at 30 and 20 FSW stops."

"Why is helium-oxygen (HeO2) used instead of air for deep diving?"

"Helium-oxygen mixtures are used for diving deeper than approximately 150-200 FSW because helium does not cause nitrogen narcosis, allows faster ascent and shorter decompression times compared to air at equivalent depths, and avoids high-pressure nervous syndrome better than air at extreme depths. HeO2 is the standard breathing gas for deep surface-supplied commercial diving operations."

"What are the gas switches in USN HeO2 decompression?"

"USN Table 12-4 specifies three gas phases during decompression: (1) Bottom Mix (HeO2) for all stops at 50 FSW and deeper; (2) Switch to 50% O2 at the 40 FSW stop; (3) Switch to 100% O2 at the 30 FSW and 20 FSW stops. These gas switches are mandatory — they accelerate decompression and reduce inert gas loading."

"What is the maximum depth covered by USN HeO2 tables?"

"USN Table 12-4 explicitly covers surface-supplied helium-oxygen diving to depths beyond 380 FSW, with exceptional exposure procedures for deep dives. The table provides decompression schedules for standard and exceptional exposure dives, with bottom times at each depth section clearly showing where Commanding Officer authorization is required for exceptional exposures."

"What is the MK 16 MOD 1 UBA and how do its tables differ?"

"The MK 16 MOD 1 UBA (Underwater Breathing Apparatus) is a closed-circuit rebreather used by U.S. Navy divers. Its decompression tables differ from open-circuit surface-supplied tables because the rebreather maintains a constant partial pressure of oxygen (PPO2) throughout the dive, which changes the decompression obligation compared to open-circuit breathing. The MK 16 tables specify procedures for different PPO2 setpoints and depth ranges."

"How does surface decompression work with HeO2 diving?"

"Surface decompression (SurDO2) with HeO2 involves ascending from the last in-water stop, transferring the diver to a deck recompression chamber, and completing the remaining decompression obligation breathing 100% oxygen under pressure. The \"Chamber O2 Periods\" column in Table 12-4 specifies the number of 30-minute oxygen breathing periods required in the chamber after surfacing."

USN Helium-Oxygen Dive Tables — U.S. Navy Diving Manual Rev 7

Source: SS521-AG-PRO-010, U.S. Navy Diving Manual, Revision 7, 01 December 2016 NAVSEA Reference: Published by Direction of Commander, Naval Sea Systems Command

CRITICAL WARNING: These tables are transcribed from the official USN Diving Manual Revision 7. They must be verified against the original publication before operational use. Transcription errors, however unlikely, could be fatal. Always cross-reference with the official NAVSEA publication.

Opens print dialog — choose "Save as PDF" to download

About These Tables

These tables apply to helium-oxygen (HeO2) and mixed gas diving using surface-supplied equipment (SSDS) and the MK 16 MOD 1 closed-circuit UBA. HeO2 is the standard breathing gas for deep commercial and naval diving operations where nitrogen narcosis and extended air decompression would be limiting factors.

Key differences from air tables:

No nitrogen narcosis at depth (helium is narcosis-free)
Faster uptake and elimination kinetics than nitrogen
Gas switches during decompression (HeO2 → 50% O2 → 100% O2) dramatically shorten decompression time
Chamber oxygen periods required post-dive
Commanding Officer authorization required for exceptional exposure bottom times

Table 12-4. Surface-Supplied Helium-Oxygen Decompression Table

(DESCENT RATE 75 FPM — ASCENT RATE 30 FPM)

Gas Switches:

Bottom Mix (HeO2): All stops at 50 FSW and deeper
50% O2: Stop at 40 FSW
100% O2: Stops at 30 and 20 FSW

Notes:

Stop times (min) include travel time, except first HeO2 stop and first O2 stop
“Chamber O2 Periods” indicates required post-dive chamber oxygen breathing periods (each period = 30 minutes)
Bottom times listed after “Exceptional Exposure” line require Commanding Officer’s authorization

60 FSW

Max O2 = 40.0% | Min O2 = 14.0%

Bottom Time (min)	Time to 1st Stop (M:S)	40 ft	30 ft	20 ft	Chamber O2 Periods
10	2:00			0	0
20	2:00			0	0
30	2:00			0	0
40	2:00			0	0
60	0:40	10	11	16	1
80	0:40	10	13	22	2
100	0:40	10	16	27	2
120	0:40	10	17	28	2

70 FSW

Max O2 = 40.0% | Min O2 = 14.0%

Bottom Time (min)	Time to 1st Stop (M:S)	40 ft	30 ft	20 ft	Chamber O2 Periods
10	2:20			0	0
20	2:20			0	0
30	2:20			0	0
40	1:00	10	10	16	1
60	1:00	10	14	24	2
80	1:00	10	18	30	2
100	1:00	10	19	34	2
120	1:00	10	21	37	2

80 FSW

Max O2 = 38.0% | Min O2 = 14.0%

Bottom Time (min)	Time to 1st Stop (M:S)	40 ft	30 ft	20 ft	Chamber O2 Periods
10	2:40			0	0
20	2:40			0	0
25	2:40			0	0
30	1:20	10	11	16	1
40	1:20	10	13	21	2
60	1:20	10	18	32	2
80	1:20	10	21	38	2
100	1:20	10	24	42	3
120	1:20	10	25	45	3

90 FSW

Max O2 = 34.9% | Min O2 = 14.0%

Bottom Time (min)	Time to 1st Stop (M:S)	50 ft	40 ft	30 ft	20 ft	Chamber O2 Periods
10	3:00				0	0
20	3:00				0	0
25	1:40	10		10	15	1
30	1:40	10		12	19	2
40	1:40	10		15	25	2
60	1:40	10		20	37	2
80	1:40	10		23	43	3
100	1:40	10		27	50	3
120	1:40	10	10	29	54	3

100 FSW

Max O2 = 40.0% | Min O2 = 16.0%

Bottom Time (min)	Time to 1st Stop (M:S)	50 ft	40 ft	30 ft	20 ft	Chamber O2 Periods
10	3:20				0	0
20	1:40	10		10	14	1
25	1:40	10		11	17	1
30	1:40	10		13	22	2
40	1:40	10		17	29	2
60	1:40	10	10	22	41	3
80	1:40	10	10	27	50	3
100	1:40	10	10	30	56	4
120	1:40	10	10	32	60	4

110 FSW

Max O2 = 30.0% | Min O2 = 14.0%

Bottom Time (min)	Time to 1st Stop (M:S)	40 ft	30 ft	20 ft	Chamber O2 Periods	Exposure
10	2:20	10	8	11	1	Normal
20	2:20	10	12	20	1	Normal
30	2:20	10	17	28	2	Normal
40	2:20	10	20	36	2	Normal
60	2:20	10	27	49	3	Normal
80	2:20	10	31	58	3	Normal
100	2:20	10	33	62	4	Normal
120	2:20	10	35	64	4	EE

120 FSW

Max O2 = 28.0% | Min O2 = 14.0%

Bottom Time (min)	Time to 1st Stop (M:S)	50 ft	40 ft	30 ft	20 ft	Chamber O2 Periods	Exposure
10	2:40		10	9	13	1	Normal
20	2:40		10	14	23	2	Normal
30	2:40		10	19	33	2	Normal
40	2:40		10	23	42	3	Normal
60	2:40		10	30	55	3	Normal
80	2:40		10	34	63	4	Normal
100	2:40		10	36	66	4	Normal
120	2:20	10	10	35	65	4	EE

130 FSW

Max O2 = 26.3% | Min O2 = 14.0%

Bottom Time (min)	Time to 1st Stop (M:S)	60 ft	50 ft	40 ft	30 ft	20 ft	Chamber O2 Periods	Exposure
10	2:40		10	10	6	8	1	Normal
20	2:40		10	10	12	19	1	Normal
30	2:40		10	10	18	30	2	Normal
40	2:20	7	10	10	22	40	3	Normal
60	2:20	7	10	10	29	52	3	Normal
80	2:20	7	10	10	33	60	3	Normal
100	2:20	7	10	10	35	64	4	EE
120	2:20	7	11	11	35	66	4	EE

140 FSW

Max O2 = 24.8% | Min O2 = 14.0%

Bottom Time (min)	Time to 1st Stop (M:S)	60 ft	50 ft	40 ft	30 ft	20 ft	Chamber O2 Periods	Exposure
10	3:00		10	10	6	8	1	Normal
20	3:00		10	10	12	19	1	Normal
30	3:00		10	10	18	30	2	Normal
40	2:40	7	10	10	22	40	2	Normal
60	2:40	7	10	10	29	52	3	Normal
80	2:40	7	10	10	33	60	3	Normal
100	2:40	7	10	10	35	64	4	EE
120	2:40	7	11	11	35	66	4	EE

150 FSW

Max O2 = 23.4% | Min O2 = 14.0%

Bottom Time (min)	Time to 1st Stop (M:S)	60 ft	50 ft	40 ft	30 ft	20 ft	Chamber O2 Periods	Exposure
10	3:20		10	10	7	8	1	Normal
20	3:00	7	10	10	14	22	2	Normal
30	3:00	7	10	10	19	34	2	Normal
40	3:00	7	10	10	24	44	3	Normal
60	3:00	7	10	10	31	56	3	Normal
80	3:00	7	10	10	35	64	4	Normal
100	3:00	7	13	13	36	66	4	EE
120	3:00	9	16	16	36	66	5	EE

160 FSW

Max O2 = 22.2% | Min O2 = 14.0%

Bottom Time (min)	Time to 1st Stop (M:S)	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Chamber O2 Periods	Exposure
10	3:20		7	10	10	8	10	1	Normal
20	3:20		7	10	10	15	24	2	Normal
30	3:20		7	10	10	21	37	2	Normal
40	3:20		7	10	10	26	47	3	Normal
60	3:00	7	6	10	10	30	56	3	Normal
80	3:00	7	9	10	10	35	66	4	EE
100	3:00	7	13	14	14	35	66	5	EE
120	3:00	7	17	17	17	36	66	5	EE

170 FSW

Max O2 = 21.1% | Min O2 = 14.0%

Bottom Time (min)	Time to 1st Stop (M:S)	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Chamber O2 Periods	Exposure
10	3:20		7	0	10	10	8	12	1	Normal
20	3:20		7	0	10	10	16	28	2	Normal
30	3:20		7	1	10	10	23	42	3	Normal
40	3:20		7	4	10	10	28	52	3	Normal
60	3:20		7	10	10	10	33	62	4	Normal
80	3:20		9	14	14	14	35	66	4	EE
100	3:00	7	5	18	18	18	36	66	5	EE
120	3:00	7	9	21	21	21	36	66	5	EE

180 FSW

Max O2 = 20.1% | Min O2 = 14.0%

Bottom Time (min)	Time to 1st Stop (M:S)	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Chamber O2 Periods	Exposure
10	3:40		7	0	10	10	9	14	1	Normal
20	3:40		7	0	10	10	17	30	2	Normal
30	3:40		7	4	10	10	25	45	3	Normal
40	3:20	7	0	8	10	10	30	54	3	Normal
60	3:20	7	5	11	11	11	35	64	4	Normal
80	3:20	7	9	15	15	15	36	66	4	EE
100	3:20	7	13	19	19	19	36	66	5	EE
120	3:20	7	17	23	23	23	36	66	6	EE

190 FSW

Max O2 = 19.2% | Min O2 = 14.0%

Bottom Time (min)	Time to 1st Stop (M:S)	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Chamber O2 Periods	Exposure
10	4:00			7	0	10	10	10	15	1	Normal
20	3:40		7	0	2	10	10	19	34	2	Normal
30	3:40		7	0	7	10	10	26	46	3	Normal
40	3:40		7	4	9	10	10	31	56	3	Normal
60	3:40		7	9	13	13	13	34	62	4	EE
80	3:20	7	3	13	18	18	18	36	66	5	EE
100	3:20	7	6	16	21	21	21	36	66	6	EE
120	3:20	7	8	20	23	23	23	36	66	7	EE

200 FSW

Max O2 = 18.4% | Min O2 = 14.0%

Bottom Time (min)	Time to 1st Stop (M:S)	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Chamber O2 Periods	Exposure
10	4:00		7	0	0	10	10	11	17	1	Normal
20	4:00		7	0	4	10	10	20	36	2	Normal
30	3:40	7	0	3	7	10	10	27	50	3	Normal
40	3:40	7	0	7	10	10	10	31	58	3	Normal
60	3:40	7	4	10	14	14	14	35	66	4	EE
80	3:40	7	8	14	18	18	18	36	66	5	EE
100	3:40	7	12	17	23	23	23	36	66	6	EE
120	3:40	8	15	21	23	23	23	36	66	7	EE

210 FSW

Max O2 = 17.7% | Min O2 = 10.0%

Bottom Time (min)	Time to 1st Stop (M:S)	100 ft	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Chamber O2 Periods	Exposure
10	4:20			7	0	0	10	10	12	19	1	Normal
20	4:00		7	0	1	6	10	10	22	38	2	Normal
30	4:00		7	0	6	7	10	10	29	53	3	Normal
40	4:00		7	3	9	10	10	10	33	60	3	Normal
60	3:40	7	0	9	11	17	17	17	35	66	5	EE
80	3:40	7	3	11	15	20	20	20	36	66	6	EE
100	3:40	7	6	14	19	23	23	23	36	66	7	EE
120	3:40	7	8	18	23	23	23	23	36	66	7	EE

220 FSW

Max O2 = 17.0% | Min O2 = 10.0%

Bottom Time (min)	Time to 1st Stop (M:S)	100 ft	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Chamber O2 Periods	Exposure
10	4:40			7	0	2	10	10	13	20	1	Normal
20	4:20		7	0	3	7	10	10	23	41	3	Normal
30	4:20		7	2	6	9	10	10	30	54	3	Normal
40	4:00	7	0	6	9	11	11	11	34	62	4	Normal
60	4:00	7	4	9	12	18	18	18	36	66	5	EE
80	4:00	7	8	12	17	21	21	21	36	66	6	EE
100	4:00	7	12	15	20	23	23	23	36	66	7	EE
120	4:00	8	14	19	23	23	23	23	36	66	8	EE

230 FSW

Max O2 = 16.3% | Min O2 = 10.0%

Bottom Time (min)	Time to 1st Stop (M:S)	110 ft	100 ft	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Chamber O2 Periods	Exposure
10	4:40			7	0	0	3	10	10	14	22	2	Normal
20	4:20		7	0	0	3	4	7	10	24	44	3	Normal
30	4:20		7	0	0	5	7	10	10	31	57	3	Normal
40	4:00	7	0	3	7	9	13	13	13	34	64	4	Normal
60	4:00	7	0	8	10	14	18	18	18	36	66	6	EE
80	4:00	7	3	10	14	18	23	23	23	36	66	7	EE
100	4:00	7	6	12	17	23	23	23	23	36	66	8	EE
120	4:00	7	7	16	19	23	23	23	23	36	66	8	EE

240 FSW

Max O2 = 15.7% | Min O2 = 10.0%

Bottom Time (min)	Time to 1st Stop (M:S)	110 ft	100 ft	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Chamber O2 Periods	Exposure
10	4:40			7	0	0	3	4	10	14	24	2	Normal
20	4:40		7	0	0	3	5	7	10	25	46	3	Normal
30	4:20	7	0	0	3	6	7	10	10	32	58	3	Normal
40	4:20	7	0	5	8	9	14	14	14	35	64	4	Normal
60	4:20	7	4	8	11	14	19	19	19	36	66	6	EE
80	4:20	7	7	11	16	18	23	23	23	36	66	7	EE
100	4:20	7	10	14	19	23	23	23	23	36	66	8	EE
120	4:00	7	3	12	17	19	23	23	23	23	36	66	8

250 FSW

Max O2 = 15.2% | Min O2 = 10.0%

Bottom Time (min)	Time to 1st Stop (M:S)	120 ft	110 ft	100 ft	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Chamber O2 Periods	Exposure
10	5:00			7	0	0	3	4	10	10	15	25	2	Normal
20	4:40		7	0	0	0	3	6	7	10	26	47	3	Normal
30	4:40	7	0	0	0	4	6	8	10	10	32	60	4	Normal
40	4:40	7	0	2	5	9	9	14	14	14	35	64	4	Normal
60	4:20	7	0	7	9	12	16	21	21	21	36	66	6	EE
80	4:20	7	3	9	13	15	21	23	23	23	36	66	7	EE
100	4:20	7	6	11	14	19	23	23	23	23	36	66	8	EE
120	4:20	7	8	13	19	20	23	23	23	23	36	66	8	EE

260 FSW

Max O2 = 14.6% | Min O2 = 10.0%

Bottom Time (min)	Time to 1st Stop (M:S)	120 ft	110 ft	100 ft	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Chamber O2 Periods	Exposure
10	5:00			7	0	0	0	4	4	10	16	27	2	Normal
20	5:00		7	0	0	2	3	4	6	7	27	50	3	Normal
30	4:40	7	0	0	2	5	6	9	10	10	33	62	4	Normal
40	4:40	7	0	3	8	9	10	15	15	15	35	64	5	Normal
60	4:40	7	3	7	10	14	16	21	21	21	36	66	6	EE
80	4:40	7	6	10	13	17	23	23	23	23	36	66	7	EE
100	4:20	7	2	9	13	16	20	23	23	23	23	36	66	8
120	4:20	7	4	11	14	19	20	23	23	23	23	36	66	8

270 FSW

Max O2 = 14.2% | Min O2 = 10.0%

Bottom Time (min)	Time to 1st Stop (M:S)	130 ft	120 ft	110 ft	100 ft	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Chamber O2 Periods	Exposure
10	5:20				7	0	0	0	3	3	4	18	28	2	Normal
20	5:00		7	0	0	0	0	3	6	6	8	17	29	2	Normal
30	5:00		7	0	0	2	5	5	9	13	13	34	62	4	Normal
40	4:40	7	0	2	5	8	8	12	16	16	16	35	66	5	EE
60	4:40	7	0	6	8	10	14	19	23	23	23	36	66	6	EE
80	4:40	7	3	8	11	14	17	23	23	23	23	36	66	7	EE
100	4:40	7	5	11	13	16	20	23	23	23	23	36	66	8	EE
120	4:40	7	8	12	16	19	20	23	23	23	23	36	66	8	EE

280 FSW

Max O2 = 13.7% | Min O2 = 10.0%

Bottom Time (min)	Time to 1st Stop (M:S)	130 ft	120 ft	110 ft	100 ft	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Chamber O2 Periods	Exposure
10	5:40				7	0	0	0	3	3	4	18	31	2	Normal
20	5:20		7	0	0	0	0	4	6	7	7	30	54	2	Normal
30	5:00	7	0	1	5	5	9	9	12	12	12	35	64	4	Normal
40	5:00	7	0	4	6	8	9	12	17	17	17	35	66	5	EE
60	5:00	7	4	6	8	12	15	18	23	23	23	36	66	7	EE
80	4:40	7	0	7	9	11	15	17	23	23	23	23	36	66	8
100	4:40	7	2	9	11	15	17	20	23	23	23	23	36	66	8
120	4:40	7	4	11	13	16	19	20	23	23	23	23	36	66	8

290 FSW

Max O2 = 13.3% | Min O2 = 10.0%

Bottom Time (min)	Time to 1st Stop (M:S)	140 ft	130 ft	120 ft	110 ft	100 ft	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Chamber O2 Periods	Exposure
10	5:40				7	0	0	0	4	3	4	19	33	2	Normal
20	5:20		7	0	0	0	2	0	6	6	9	30	56	2	Normal
30	5:20	7	0	0	2	5	5	9	9	14	14	34	63	5	Normal
40	5:20	7	0	5	7	8	11	13	17	17	17	35	66	5	EE
60	5:00	7	0	6	7	9	12	15	20	23	23	23	36	66	7	EE
80	5:00	7	2	8	10	12	16	19	23	23	23	23	36	66	8	EE
100	5:00	7	5	10	12	15	19	20	23	23	23	23	36	66	8	EE
120	5:00	7	8	11	16	17	19	20	23	23	23	23	36	66	8	EE

300 FSW

Max O2 = 12.9% | Min O2 = 10.0%

All bottom times are Exceptional Exposure.

Bottom Time (min)	Time to 1st Stop (M:S)	140 ft	130 ft	120 ft	110 ft	100 ft	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Chamber O2 Periods
10	6:00			7	0	0	0	4	3	4	10	10	19	33	2
20	5:40		7	0	0	2	6	6	6	9	10	10	30	56	3
30	5:40		7	0	2	5	5	9	9	14	14	14	34	63	5
40	5:40		7	0	5	7	8	11	13	17	17	17	35	66	6
60	5:20	7	0	6	7	9	12	15	20	23	23	23	36	66	7
80	5:20	7	2	8	10	12	16	19	23	23	23	23	36	66	8
100	5:20	7	5	10	12	15	19	20	23	23	23	23	36	66	8
120	5:20	7	8	11	16	17	19	20	23	23	23	23	36	66	8

310 FSW

Max O2 = 12.5% | Min O2 = 10.0%

All bottom times are Exceptional Exposure.

Bottom Time (min)	Time to 1st Stop (M:S)	150 ft	140 ft	130 ft	120 ft	110 ft	100 ft	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Chamber O2 Periods
10	6:00			7	0	0	0	3	3	3	7	10	10	21	36	2
20	5:40		7	0	0	2	4	5	6	7	10	10	10	31	57	4
30	5:40		7	0	2	4	5	7	8	11	15	15	15	35	66	5
40	5:20	7	0	1	4	6	7	8	12	15	19	19	19	36	66	7
60	5:20	7	0	5	6	9	11	13	17	20	23	23	23	36	66	8
80	5:20	7	3	7	9	11	13	17	20	23	23	23	23	36	66	8
100	5:20	7	5	9	11	13	17	19	20	23	23	23	23	36	66	8
120	5:20	7	7	12	13	16	17	19	20	23	23	23	23	36	66	8

320 FSW

Max O2 = 12.2% | Min O2 = 10.0%

All bottom times are Exceptional Exposure.

Bottom Time (min)	Time to 1st Stop (M:S)	160 ft	150 ft	140 ft	130 ft	120 ft	110 ft	100 ft	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Chamber O2 Periods
10	6:20				7	0	0	0	4	3	3	7	10	10	21	38	2
20	6:00			7	0	0	3	5	5	6	8	10	10	10	32	59	4
30	5:40		7	0	0	4	4	6	7	9	11	17	17	17	35	66	5
40	5:40		7	0	4	4	6	7	9	12	16	20	20	20	36	66	6
60	5:20	7	0	2	6	8	9	11	14	17	23	23	23	23	36	66	8
80	5:20	7	0	6	8	8	13	14	19	20	23	23	23	23	36	66	8
100	5:20	7	2	7	10	13	16	17	19	20	23	23	23	23	36	66	8
120	5:20	7	4	9	12	13	16	17	19	20	23	23	23	23	36	66	8

330 FSW

Max O2 = 11.8% | Min O2 = 10.0%

All bottom times are Exceptional Exposure.

Bottom Time (min)	Time to 1st Stop (M:S)	170 ft	160 ft	150 ft	140 ft	130 ft	120 ft	110 ft	100 ft	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Chamber O2 Periods
10	6:20				7	0	0	0	2	3	3	4	7	10	10	22	40	2
20	6:00			7	0	0	2	3	4	6	5	10	10	10	10	33	60	4
30	6:00			7	0	1	4	5	6	8	8	13	17	17	17	35	66	6
40	5:40		7	0	1	4	5	7	7	10	12	17	22	22	22	36	66	7
60	5:40		7	0	5	6	8	9	11	15	20	23	23	23	23	36	66	8
80	5:40		7	2	7	8	10	13	15	19	20	23	23	23	23	36	66	8
100	5:40		7	5	9	9	13	16	17	19	20	23	23	23	23	36	66	8
120	5:20	7	1	7	10	13	15	16	17	19	20	23	23	23	23	36	66	8

340 FSW

Max O2 = 11.5% | Min O2 = 10.0%

All bottom times are Exceptional Exposure.

Bottom Time (min)	Time to 1st Stop (M:S)	170 ft	160 ft	150 ft	140 ft	130 ft	120 ft	110 ft	100 ft	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Chamber O2 Periods
10	6:40				7	0	0	0	3	3	3	4	7	10	10	23	41	3
20	6:20			7	0	0	2	4	5	7	8	9	10	10	10	33	60	5
30	6:00		7	0	0	3	5	5	6	8	9	13	18	18	18	35	66	6
40	6:00		7	0	2	4	6	7	8	10	13	16	22	22	22	36	66	7
60	5:40	7	0	3	5	6	9	10	13	16	18	21	23	23	23	36	66	8
80	5:40	7	0	7	7	8	11	13	15	19	20	23	23	23	23	36	66	8
100	5:40	7	2	8	8	12	13	16	17	19	20	23	23	23	23	36	66	8
120	5:40	7	4	9	11	13	15	16	17	19	20	23	23	23	23	36	66	8

350 FSW

Max O2 = 11.2% | Min O2 = 10.0%

All bottom times are Exceptional Exposure.

Bottom Time (min)	Time to 1st Stop (M:S)	180 ft	170 ft	160 ft	150 ft	140 ft	130 ft	120 ft	110 ft	100 ft	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Chamber O2 Periods
10	6:40				7	0	0	0	2	2	3	3	5	7	10	10	24	43	3
20	6:20			7	0	0	0	4	4	5	5	7	9	13	13	13	33	63	5
30	6:20			7	0	1	4	4	5	7	8	11	13	18	18	18	36	66	6
40	6:00		7	0	1	3	5	6	7	8	11	14	17	23	23	23	36	66	7
60	6:00		7	0	5	5	8	8	11	12	16	19	23	23	23	23	36	66	8
80	6:00		7	2	7	7	10	11	13	17	19	20	23	23	23	23	36	66	8
100	5:40	7	0	6	8	9	11	15	16	17	19	20	23	23	23	23	36	66	8
120	5:40	7	1	7	9	12	14	15	16	17	19	20	23	23	23	23	36	66	8

360 FSW

Max O2 = 10.9% | Min O2 = 10.0%

All bottom times are Exceptional Exposure.

Bottom Time (min)	Time to 1st Stop (M:S)	170 ft	160 ft	150 ft	140 ft	130 ft	120 ft	110 ft	100 ft	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Chamber O2 Periods
10	7:00			7	0	0	0	2	2	3	3	7	7	10	10	25	44	3
20	6:40		7	0	0	2	3	4	5	5	8	10	13	13	13	34	63	5
30	6:20	7	0	0	3	3	5	6	7	8	11	13	19	19	19	36	66	7
40	6:20	7	0	2	4	5	7	7	9	10	14	20	23	23	23	36	66	8
60	6:20	7	2	5	6	7	9	11	14	16	19	23	23	23	23	36	66	8
80	6:00	7	0	6	6	8	11	12	14	16	19	20	23	23	23	23	36	66
100	6:00	7	2	7	8	11	13	13	16	17	19	20	23	23	23	23	36	66
120	6:00	7	4	8	10	12	14	15	16	17	19	20	23	23	23	23	36	66

370 FSW

Max O2 = 10.6% | Min O2 = 10.0%

All bottom times are Exceptional Exposure.

Bottom Time (min)	Time to 1st Stop (M:S)	180 ft	170 ft	160 ft	150 ft	140 ft	130 ft	120 ft	110 ft	100 ft	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Chamber O2 Periods
10	7:00		7	0	0	0	0	3	3	3	3	7	7	10	10	25	46	3
20	6:40	7	0	0	0	3	4	4	5	5	8	10	13	13	13	34	63	5
30	6:20	7	0	0	2	3	4	4	7	7	8	11	16	19	19	19	36	66	7
40	6:20	7	0	0	4	4	5	6	8	10	11	14	20	23	23	23	36	66	8
60	6:20	7	0	4	5	7	8	9	11	13	17	20	23	23	23	23	36	66	8
80	6:00	7	0	3	6	7	9	10	12	15	17	19	20	23	23	23	23	36	66
100	6:00	7	0	6	7	9	10	14	15	16	17	19	20	23	23	23	23	36	66
120	6:00	7	1	7	9	11	13	14	15	16	17	19	20	23	23	23	23	36	66

380 FSW

Max O2 = 10.4% | Min O2 = 10.0%

All bottom times are Exceptional Exposure.

Bottom Time (min)	Time to 1st Stop (M:S)	180 ft	170 ft	160 ft	150 ft	140 ft	130 ft	120 ft	110 ft	100 ft	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Chamber O2 Periods
10	7:20		7	0	0	0	0	3	3	3	3	7	7	10	10	25	46	3
20	7:00	7	0	0	0	3	4	4	5	5	8	10	13	13	13	34	63	6
30	6:40	7	0	0	2	3	4	4	7	7	8	11	16	19	19	19	36	66	7
40	6:40	7	0	0	4	4	5	6	8	10	11	14	20	23	23	23	36	66	8
60	6:40	7	0	4	5	7	8	9	11	13	17	20	23	23	23	23	36	66	8
80	6:20	7	0	3	6	7	9	10	12	15	17	19	20	23	23	23	23	36	66
100	6:20	7	0	6	7	9	10	14	15	16	17	19	20	23	23	23	23	36	66
120	6:20	7	1	7	9	11	13	14	15	16	17	19	20	23	23	23	23	36	66

MK 16 MOD 1 Closed-Circuit UBA Tables (1.3 ata ppO2)

(DESCENT RATE 60 FPM — ASCENT RATE 30 FPM)

The following tables apply to the MK 16 MOD 1 closed-circuit underwater breathing apparatus operating at a constant partial pressure of oxygen of 1.3 ata.

Table 15-8. No Decompression Limits and Repetitive Group Designators for 1.3 ata ppO2 N2O2 Dives

Notes:

– Diver does not acquire a repetitive group designator during dives to these depths
* Highest repetitive group that can be achieved at this depth regardless of bottom time
Depths at 160 FSW and deeper are Exceptional Exposure (require CO authorization)

Depth (fsw)	No-Stop Limit	A	B	C	D	E	F	G	H	I	J	K	L	M	N	O	Z
10	Unlimited	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–
15	Unlimited	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–
20	Unlimited	153	420	*
25	Unlimited	51	87	133	196	296	557	*
30	Unlimited	31	50	72	98	128	164	210	273	372	629	*
35	Unlimited	22	35	50	66	84	103	126	151	181	217	263	326	425	680	*
40	Unlimited	89	168	318	*
50	Unlimited	27	44	63	84	108	136	169	210	265	344	496	*
60	297	16	25	36	46	58	70	83	97	113	130	149	170	194	222	255	297
70	130	11	18	25	32	39	47	55	64	73	83	93	103	115	127	130
80	70	9	14	19	24	30	36	42	48	54	61	68	70
90	50	7	11	15	20	24	29	33	38	43	48	50
100	39	6	9	13	16	20	24	28	32	36	39
110	32	5	8	11	14	17	20	24	27	30	32
120	27	4	7	9	12	15	18	20	23	26	27
130	23	3	6	8	11	13	16	18	21	23
140	21	3	5	7	9	12	14	16	18	21
150	17	3	5	6	8	10	12	15	17
Exceptional Exposure
160	15	3	4	6	8	9	11	13	15
170	13		4	5	7	9	10	12	13
180	12		3	5	6	8	9	11	12
190	10			4	6	7	9	10

Table 15-9. Residual Nitrogen Timetable for 1.3 ata ppO2 N2O2 Dives

This table has two parts:

Surface Interval Credit Table — Determines new repetitive group after a surface interval
Residual Nitrogen Times — Minutes of residual nitrogen time for the repetitive dive

Part 1: Surface Interval Credit Table

Locate your previous repetitive group designation. Read horizontally to find the column where your surface interval falls. Read down to find your new repetitive group.

* = Dives following surface intervals longer than this are not repetitive dives. Use actual bottom times in the Tables 15-8 and 15-10 to compute decompression for such dives.

All times in h:mm format.

Previous Group	New Group: Z	O	N	M	L	K	J	I	H	G	F	E	D	C	B	A	Not Rep (>)
Z	0:10–0:52	0:53–1:44	1:45–2:37	2:38–3:29	3:30–4:21	4:22–5:13	5:14–6:06	6:07–6:58	6:59–7:50	7:51–8:42	8:43–9:34	9:35–10:27	10:28–11:19	11:20–12:13	12:14–13:30	13:31–15:50	15:50
O		0:10–0:52	0:53–1:44	1:45–2:37	2:38–3:29	3:30–4:21	4:22–5:13	5:14–6:06	6:07–6:58	6:59–7:50	7:51–8:42	8:43–9:34	9:35–10:27	10:28–11:21	11:22–12:37	12:38–14:58	14:58
N			0:10–0:52	0:53–1:44	1:45–2:37	2:38–3:29	3:30–4:21	4:22–5:13	5:14–6:06	6:07–6:58	6:59–7:50	7:51–8:42	8:43–9:34	9:35–10:29	10:30–11:45	11:46–14:05	14:05
M				0:10–0:52	0:53–1:44	1:45–2:37	2:38–3:29	3:30–4:21	4:22–5:13	5:14–6:06	6:07–6:58	6:59–7:50	7:51–8:42	8:43–9:37	9:38–10:53	10:54–13:13	13:13
L					0:10–0:52	0:53–1:44	1:45–2:37	2:38–3:29	3:30–4:21	4:22–5:13	5:14–6:06	6:07–6:58	6:59–7:50	7:51–8:44	8:45–10:01	10:02–12:21	12:21
K						0:10–0:52	0:53–1:44	1:45–2:37	2:38–3:29	3:30–4:21	4:22–5:13	5:14–6:06	6:07–6:58	6:59–7:52	7:53–9:09	9:10–11:29	11:29
J							0:10–0:52	0:53–1:44	1:45–2:37	2:38–3:29	3:30–4:21	4:22–5:13	5:14–6:06	6:07–7:00	7:01–8:16	8:17–10:36	10:36
I								0:10–0:52	0:53–1:44	1:45–2:37	2:38–3:29	3:30–4:21	4:22–5:13	5:14–6:08	6:09–7:24	7:25–9:44	9:44
H									0:10–0:52	0:53–1:44	1:45–2:37	2:38–3:29	3:30–4:21	4:22–5:16	5:17–6:32	6:33–8:52	8:52
G										0:10–0:52	0:53–1:44	1:45–2:37	2:38–3:29	3:30–4:23	4:24–5:40	5:41–8:00	8:00
F											0:10–0:52	0:53–1:44	1:45–2:37	2:38–3:31	3:32–4:48	4:49–7:08	7:08
E												0:10–0:52	0:53–1:44	1:45–2:39	2:40–3:55	3:56–6:15	6:15
D													0:10–0:52	0:53–1:47	1:48–3:03	3:04–5:23	5:23
C														0:10–0:55	0:56–2:11	2:12–4:31	4:31
B															0:10–1:16	1:17–3:36	3:36
A																0:10–2:20	2:20

Note: The Surface Interval Credit intervals for 1.3 ata ppO2 N2O2 are identical to those for Air (Table 9-8 Part 1), since both use the same nitrogen offgassing model.

Part 2: Residual Nitrogen Times (Minutes)

Enter with Dive Depth (rows) and Repetitive Group at End of Surface Interval (columns).

** = Residual Nitrogen Time cannot be determined using this table. See paragraph 9-9.1 subparagraph 8 for guidance. Substitute the ** depths in this table for those in the instructions. – = Repetitive dives to these depths are equivalent to remaining on the surface. Add the bottom time of the dive to the preceding surface interval. Use the Surface Interval Credit Table (SICT) to determine the repetitive group at the end of the dive.

Depth (fsw)	Z	O	N	M	L	K	J	I	H	G	F	E	D	C	B	A
10	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–
15	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–
20	**	**	**	**	**	**	**	**	**	**	**	**	**	**	420	153
25	**	**	**	**	**	**	**	**	**	**	556	296	196	134	88	51
30	**	**	**	**	**	**	626	372	273	211	165	129	99	73	51	31
35	**	**	671	423	325	263	218	181	152	126	104	84	67	51	36	22
40	**	**	**	**	**	**	**	**	**	**	**	**	**	311	166	88
50	**	**	**	**	**	481	339	262	209	168	135	107	84	63	44	27
60	293	252	220	192	168	148	129	112	97	83	70	58	46	36	26	16
70	153	139	126	114	103	92	82	73	64	56	47	40	32	25	18	12
80	107	98	90	82	75	68	61	54	48	42	36	30	25	19	14	9
90	82	76	70	64	59	54	48	43	38	34	29	25	20	16	12	8
100	67	62	58	53	49	44	40	36	32	28	24	21	17	13	10	7
110	57	53	49	45	41	38	34	31	28	24	21	18	15	12	9	6
120	49	46	42	39	36	33	30	27	24	21	19	16	13	10	8	5
130	43	40	38	35	32	29	27	24	22	19	17	14	12	9	7	5
140	39	36	34	31	29	26	24	22	19	17	15	13	11	8	6	4
150	35	33	31	28	26	24	22	20	18	16	14	12	10	8	6	4
160	32	30	28	26	24	22	20	18	16	14	13	11	9	7	5	4
170	30	28	26	24	22	20	19	17	15	13	12	10	8	7	5	3
180	27	26	24	22	21	19	17	16	14	12	11	9	8	6	5	3
190	25	24	22	21	19	18	16	15	13	12	10	9	7	6	4	3

Table 15-10. 1.3 ata ppO2 N2O2 Decompression Tables

(DESCENT RATE 60 FPM — ASCENT RATE 30 FPM)

Stop times (min) include travel time, except first stop.

60 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	20 ft	Total Ascent (M:S)	Rep Group
297	2:00	0	2:00	Z
300	1:20	1	3:00	Z
310	1:20	2	4:00	Z
320	1:20	3	5:00	Z
330	1:20	4	6:00	Z
Exceptional Exposure
340	1:20	5	7:00
350	1:20	6	8:00
360	1:20	7	9:00
370	1:20	8	10:00
380	1:20	9	11:00
390	1:20	10	12:00

70 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	20 ft	Total Ascent (M:S)	Rep Group
130	2:20	0	2:20	O
140	1:40	3	5:20	O
150	1:40	6	8:20	O
160	1:40	8	10:20	Z
170	1:40	10	12:20	Z
180	1:40	12	14:20	Z
190	1:40	14	16:20	Z
200	1:40	16	18:20	Z
210	1:40	19	21:20	Z
220	1:40	22	24:20	Z
230	1:40	24	26:20	Z
Exceptional Exposure
240	1:40	26	28:20
250	1:40	29	31:20
260	1:40	31	33:20
270	1:40	33	35:20
280	1:40	35	37:20
290	1:40	37	39:20
300	1:40	38	40:20
310	1:40	40	42:20
320	1:40	42	44:20
340	1:40	47	49:20
350	1:40	49	51:20

80 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	20 ft	Total Ascent (M:S)	Rep Group
70	2:40	0	2:40	L
75	2:00	2	4:40	L
80	2:00	4	6:40	M
85	2:00	5	7:40	M
90	2:00	6	8:40	N
95	2:00	7	9:40	N
100	2:00	9	11:40	N
110	2:00	12	14:40	O
120	2:00	16	18:40	O
130	2:00	20	22:40	Z
140	2:00	24	26:40	Z
150	2:00	27	29:40	Z
160	2:00	30	32:40	Z
170	2:00	34	36:40	Z
Exceptional Exposure
180	2:00	39	41:40
190	2:00	43	45:40
200	2:00	47	49:40
210	2:00	50	52:40
220	2:00	54	56:40
230	2:00	57	59:40
240	2:00	60	62:40
250	2:00	63	65:40
260	2:00	67	69:40
270	2:00	70	72:40
280	2:00	74	76:40
290	2:00	77	79:40
300	2:00	81	83:40
310	2:00	84	86:40
320	2:00	87	89:40

90 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	30 ft	20 ft	Total Ascent (M:S)	Rep Group
50	3:00		0	3:00	K
55	2:20		3	6:00	K
60	2:20		6	9:00	L
65	2:20		8	11:00	L
70	2:20		11	14:00	M
75	2:20		13	16:00	M
80	2:20		14	17:00	N
85	2:20		16	19:00	N
90	2:20		18	21:00	O
95	2:20		21	24:00	O
100	2:20		24	27:00	O
110	2:20		30	33:00	O
120	2:20		35	38:00	Z
130	2:20		40	43:00	Z
Exceptional Exposure
140	2:20		45	48:00
150	2:20		51	54:00
160	2:20		57	60:00
170	2:00	1	62	65:40
180	2:00	2	66	70:40
190	2:00	2	71	75:40

100 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	30 ft	20 ft	Total Ascent (M:S)	Rep Group
39	3:20		0	3:20	J
40	2:40		1	4:20	J
45	2:40		5	8:20	K
50	2:40		9	12:20	L
55	2:40		12	15:20	L
60	2:40		15	18:20	M
65	2:40		18	21:20	M
70	2:40		21	24:20	N
75	2:40		23	26:20	N
80	2:40		26	29:20	O
85	2:40		30	33:20	O
90	2:40		34	37:20	O
95	2:20	1	37	41:00	O
100	2:20	3	39	45:00	O
Exceptional Exposure
110	2:20	6	43	52:00
120	2:20	8	47	58:00

110 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	40 ft	30 ft	20 ft	Total Ascent (M:S)	Rep Group
32	3:40			0	3:40	J
35	3:00			3	6:40	J
40	3:00			8	11:40	K
45	3:00			13	16:40	L
50	3:00			17	20:40	L
55	3:00			21	24:40	M
60	3:00			25	28:40	M
65	3:00			28	31:40	N
70	2:40		1	30	34:20	O
75	2:40		4	32	39:20	O
80	2:40		7	34	44:20	O
Exceptional Exposure
85	2:40		9	37	49:20
90	2:40		11	39	53:20
95	2:40		13	42	58:20
100	2:40		15	44	62:20
110	2:20	3	15	49	70:00
120	2:20	6	15	56	80:00

120 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	40 ft	30 ft	20 ft	Total Ascent (M:S)	Rep Group
27	4:00			0	4:00	J
30	3:20			4	8:00	J
35	3:20			10	14:00	K
40	3:20			16	20:00	L
45	3:20			21	25:00	L
50	3:20			26	30:00	M
55	3:20			30	34:00	M
60	3:00		4	31	38:40	N
65	3:00		8	30	41:40	O
Exceptional Exposure
70	3:00		12	32	47:40
75	3:00		15	35	53:40
80	2:40	3	15	38	59:20
85	2:40	6	15	41	65:20
90	2:40	8	15	44	70:20
95	2:40	10	15	47	75:20
100	2:40	12	15	51	81:20

130 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	40 ft	30 ft	20 ft	Total Ascent (M:S)	Rep Group
23	4:20			0	4:20	I
25	3:40			2	6:20	J
30	3:40			10	14:20	K
35	3:40			17	21:20	K
40	3:40			23	27:20	L
45	3:40			29	33:20	M
50	3:20		4	30	38:00	N
55	3:20		9	30	43:00	N
Exceptional Exposure
60	3:20		14	30	48:00
65	3:00	3	15	33	54:40
70	3:00	7	15	36	61:40
75	3:00	11	15	39	68:40
80	3:00	14	15	42	74:40

140 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	50 ft	40 ft	30 ft	20 ft	Total Ascent (M:S)	Rep Group
21	4:40				0	4:40	I
25	4:00				7	11:40	J
30	4:00				16	20:40	K
35	4:00				23	27:40	L
40	3:40			2	29	35:20	L
45	3:40			7	30	41:20	M
Exceptional Exposure
50	3:20		1	12	30	47:00
55	3:20		4	15	30	53:00
60	3:20		9	15	33	61:00
65	3:20		13	15	36	68:00
70	3:00	3	15	15	40	76:40
75	3:00	7	15	15	44	84:40
80	3:00	10	15	15	50	93:40

150 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	60 ft	50 ft	40 ft	30 ft	20 ft	Total Ascent (M:S)	Rep Group
17	5:00					0	5:00	H
20	4:20					3	8:00	I
25	4:20					13	18:00	J
30	4:20					22	27:00	K
35	4:00				3	27	34:40	L
40	4:00				8	30	42:40	M
Exceptional Exposure
45	3:40			4	11	30	49:20
50	3:40			7	15	30	56:20
55	3:20		2	11	15	33	65:00
60	3:20		4	14	15	37	74:00
65	3:20		8	15	15	40	82:00
70	3:20		13	15	15	46	93:00
75	3:00	2	15	15	15	52	102:40
80	3:00	6	15	15	15	59	113:40

160 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	80 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Total Ascent (M:S)	Rep Group
Exceptional Exposure
15	5:20						0	5:20	H
20	4:40						7	12:20	J
25	4:20					1	17	23:00	K
30	4:20					3	25	33:00	L
35	4:00				1	8	28	41:40	M
40	4:00				5	10	30	49:40
45	3:40			2	7	14	30	57:20
50	3:40			5	10	15	33	67:20
55	3:40			8	14	15	36	77:20
60	3:20		3	10	15	15	41	88:00
65	3:20		5	13	15	15	48	100:00
70	3:20		8	15	15	15	55	112:00
75	3:20		13	15	15	15	61	123:00
80	3:00	3	15	15	15	15	68	134:40

170 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Total Ascent (M:S)	Rep Group
Exceptional Exposure
13	5:40						0	5:40	H
15	5:00						2	7:40	I
20	5:00						12	17:40	J
25	4:40					3	20	28:20	K
30	4:20				3	5	26	39:00	L
35	4:00			1	5	8	30	48:40
40	4:00			4	7	12	30	57:40
45	4:00			8	8	15	32	67:40
50	3:40		4	7	13	15	36	79:20
55	3:40		7	9	15	15	41	91:20
60	3:20	2	7	14	15	15	48	105:00

180 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Total Ascent (M:S)	Rep Group
Exceptional Exposure
12	6:00							0	6:00	H
15	5:20							4	10:00	I
20	5:00						2	14	21:40	K
25	4:40					3	3	23	34:20	L
30	4:20				2	4	7	27	45:00
35	4:00			1	3	8	9	30	55:40
40	4:00			2	7	8	14	30	65:40
45	4:00			6	7	11	15	35	78:40
50	3:40		2	8	8	15	15	40	92:20
55	3:40		5	8	12	15	15	49	108:20
60	3:20	1	7	9	15	15	15	57	123:00

190 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Total Ascent (M:S)	Rep Group
Exceptional Exposure
10	6:20							0	6:20	G
15	5:40							6	12:20	J
20	5:00					1	4	16	26:40	K
25	4:40				2	4	4	24	39:20	L
30	4:20			2	3	5	8	29	52:00
35	4:20			4	5	8	11	30	63:00
40	4:00		2	5	8	8	15	34	76:40
45	4:00		4	8	7	14	15	39	91:40
50	3:40	1	7	8	11	15	15	47	108:20
55	3:40	4	8	8	15	15	15	56	125:20
60	3:40	7	7	13	15	15	15	65	141:20

MK 16 MOD 1 Closed-Circuit UBA Tables — 1.3 ata ppO2 HeO2

The following tables apply to the MK 16 MOD 1 closed-circuit underwater breathing apparatus operating at a constant partial pressure of oxygen of 1.3 ata, using helium-oxygen (HeO2) as the breathing gas.

Table 15-11. No Decompression Limits and Repetitive Group Designators for 1.3 ata ppO2 HeO2 Dives

Notes:

– Diver does not acquire a repetitive group designator during dives to these depths
* Highest repetitive group that can be achieved at this depth regardless of bottom time
Blank cells = Group not achievable at this depth

Depth (fsw)	No-Stop Limit	A	B	C	D	E	F	G	H	I	J	K	L	M	N	O	Z
10	Unlimited	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–
15	Unlimited	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–
20	Unlimited	129	269	*
25	Unlimited	45	72	106	146	200	278	425	*
30	332	27	43	60	78	100	124	152	185	227	281	332
35	190	19	30	41	54	67	81	97	114	133	154	178	190
40	Unlimited	122	246	*
50	325	27	43	59	78	99	123	150	183	223	276	325
60	134	15	23	32	41	51	61	71	83	95	108	123	134
70	86	11	16	22	28	34	41	47	54	61	69	77	85	86
80	63	8	12	17	21	26	30	35	40	45	51	56	62	63
90	44	6	10	13	17	20	24	28	32	36	40	44
100	31	5	8	11	14	17	20	23	26	30	31
110	24	4	7	9	12	14	17	20	22	24
120	20	4	6	8	10	13	15	17	19	20
130	17	3	5	7	9	11	13	15	17
140	15	3	4	6	8	10	12	13	15
150	13	3	4	6	7	9	10	12	13
160	12		3	5	6	8	9	11	12
170	11		3	4	6	7	9	10	11
180	10		3	4	5	6	8	9	10
190	9			4	5	6	7	8	9
200	8				4	5	7	8

Table 15-12. Residual Helium Timetable for 1.3 ata ppO2 HeO2 Dives

Part 1: Surface Interval Credit Table (Helium)

Locate the diver’s repetitive group designation from his previous dive in the “Previous Group” column. Read across to find the interval in which the diver’s surface interval lies. The column header shows the new repetitive group designation.

Minimum surface interval for a repetitive dive is 0:10 (hours:minutes).
Surface intervals less than 0:10 are not permitted.
Intervals beyond the last value marked with * are not repetitive – use actual bottom times with Tables 15-11 and 15-13.

Previous Group	Z	O	N	M	L	K	J	I	H	G	F	E	D	C	B	A	Not Rep (>)
A																0:10-2:01	2:01
B															0:10-1:10	1:11-3:11	3:11
C														0:10-0:50	0:51-2:00	2:01-4:01	4:01
D													0:10-0:42	0:43-1:32	1:33-2:43	2:44-4:44	4:44
E												0:10-0:42	0:43-1:25	1:26-2:15	2:16-3:25	3:26-5:26	5:26
F											0:10-0:42	0:43-1:25	1:26-2:07	2:08-2:57	2:58-4:08	4:09-6:08	6:08
G										0:10-0:42	0:43-1:25	1:26-2:07	2:08-2:49	2:50-3:39	3:40-4:50	4:51-6:51	6:51
H									0:10-0:42	0:43-1:25	1:26-2:07	2:08-2:49	2:50-3:32	3:33-4:22	4:23-5:32	5:33-7:33	7:33
I								0:10-0:42	0:43-1:25	1:26-2:07	2:08-2:49	2:50-3:32	3:33-4:14	4:15-5:04	5:05-6:15	6:16-8:15	8:15
J							0:10-0:42	0:43-1:25	1:26-2:07	2:08-2:49	2:50-3:32	3:33-4:14	4:15-4:56	4:57-5:46	5:47-6:57	6:58-8:58	8:58
K						0:10-0:42	0:43-1:25	1:26-2:07	2:08-2:49	2:50-3:32	3:33-4:14	4:15-4:56	4:57-5:39	5:40-6:29	6:30-7:39	7:40-9:40	9:40
L					0:10-0:42	0:43-1:25	1:26-2:07	2:08-2:49	2:50-3:32	3:33-4:14	4:15-4:56	4:57-5:39	5:40-6:21	6:22-7:11	7:12-8:22	8:23-10:22	10:22
M				0:10-0:42	0:43-1:25	1:26-2:07	2:08-2:49	2:50-3:32	3:33-4:14	4:15-4:56	4:57-5:39	5:40-6:21	6:22-7:03	7:04-7:53	7:54-9:04	9:05-11:05	11:05
N			0:10-0:42	0:43-1:25	1:26-2:07	2:08-2:49	2:50-3:32	3:33-4:14	4:15-4:56	4:57-5:39	5:40-6:21	6:22-7:03	7:04-7:46	7:47-8:36	8:37-9:46	9:47-11:47	11:47
O		0:10-0:42	0:43-1:25	1:26-2:07	2:08-2:49	2:50-3:32	3:33-4:14	4:15-4:56	4:57-5:39	5:40-6:21	6:22-7:03	7:04-7:46	7:47-8:28	8:29-9:18	9:19-10:29	10:30-12:29	12:29
Z	0:10-0:42	0:43-1:25	1:26-2:07	2:08-2:49	2:50-3:32	3:33-4:14	4:15-4:56	4:57-5:39	5:40-6:21	6:22-7:03	7:04-7:46	7:47-8:28	8:29-9:10	9:11-10:00	10:01-11:11	11:12-13:12	13:12

Note: All surface intervals are in hours:minutes format. The “Not Rep (>)” column shows the threshold beyond which the dive is no longer considered repetitive.

Part 2: Residual Helium Times (Minutes)

After determining the new repetitive group designation from Part 1, read down the appropriate column to the row matching the repetitive dive depth to find the Residual Helium Time (RHT) in minutes. Add the RHT to the planned bottom time of the repetitive dive to obtain the equivalent single dive time for decompression planning.

Depth (fsw)	Z	O	N	M	L	K	J	I	H	G	F	E	D	C	B	A
10	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–
15	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–
20	**	**	**	**	**	**	**	**	**	**	**	**	**	**	269	129
25	**	**	**	**	**	**	**	**	**	425	279	201	147	106	73	45
30	+	+	+	+	515	361	281	227	186	152	124	100	79	60	43	28
35	420	338	283	241	207	179	155	133	114	97	82	68	54	42	31	20
40	**	**	**	**	**	**	**	**	**	**	**	**	**	**	240	120
50	+	+	+	+	474	345	272	220	181	149	122	98	78	59	42	27
60	217	194	173	154	137	122	108	95	83	71	61	51	41	32	24	16
70	122	112	102	93	85	77	69	61	54	47	41	34	28	22	17	11
80	86	80	73	68	62	56	51	46	40	36	31	26	22	17	13	9
90	67	62	57	53	49	44	40	36	32	29	25	21	17	14	10	7
100	55	51	47	44	40	37	33	30	27	24	21	18	15	12	9	6
110	46	43	40	37	34	31	29	26	23	20	18	15	13	10	8	5
120	40	37	35	32	30	27	25	23	20	18	16	13	11	9	7	5
130	35	33	31	29	27	24	22	20	18	16	14	12	10	8	6	4
140	32	30	28	26	24	22	20	18	16	14	13	11	9	7	6	4
150	29	27	25	23	22	20	18	17	15	13	12	10	8	7	5	4
160	26	25	23	21	20	18	17	15	14	12	11	9	8	6	5	3
170	24	23	21	20	18	17	15	14	13	11	10	8	7	6	4	3
180	22	21	20	18	17	16	14	13	12	10	9	8	7	5	4	3
190	21	20	18	17	16	15	13	12	11	10	9	7	6	5	4	3
200	20	18	17	16	15	14	13	11	10	9	8	7	6	5	4	3

Table Notes

– Repetitive dives to these depths are equivalent to remaining on the surface. Add the bottom time of the dive to the preceding surface interval. Use the Surface Interval Credit Table (SICT) to determine the repetitive group at the end of the dive.
** Residual Helium Time cannot be determined using this table. See paragraph 9-9.1 subparagraph 8 for guidance. Substitute the ** depths in this table for those in the instructions.
+ Read vertically down to the 35 or 60 fsw repetitive dive depth to obtain the RHT. Decompress on the 35 or 60 fsw table.

Table 15-13. 1.3 ata ppO2 HeO2 Decompression Tables

(DESCENT RATE 60 FPM — ASCENT RATE 30 FPM)

Stop times (min) include travel time, except first stop.

30 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	20 ft	Total Ascent (M:S)
332	1:00	0	1:00
340	0:20	4	5:00
360	0:20	13	14:00
420	0:20	34	35:00
480	0:20	48	49:00
540	0:20	59	60:00
600	0:20	70	71:00
660	0:20	87	88:00
720	0:20	101	102:00

35 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	20 ft	Total Ascent (M:S)	Rep Group
190	1:10	0	1:10	L
200	0:30	12	13:10	L
210	0:30	23	24:10
220	0:30	33	34:10
230	0:30	42	43:10
240	0:30	50	51:10
270	0:30	71	72:10
300	0:30	89	90:10
330	0:30	103	104:10
360	0:30	115	116:10
390	0:30	126	127:10
420	0:30	145	146:10
450	0:30	162	163:10
480	0:30	177	178:10

50 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	20 ft	Total Ascent (M:S)	Rep Group
325	1:40	0	1:40	K
330	1:00	1	2:40	K
340	1:00	2	3:40	K
350	1:00	3	4:40	K
360	1:00	5	6:40	K
420	1:00	11	12:40
480	1:00	15	16:40
540	1:00	18	19:40
600	1:00	21	22:40
660	1:00	25	26:40
720	1:00	29	30:40

60 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	20 ft	Total Ascent (M:S)	Rep Group
134	2:00	0	2:00	L
140	1:20	3	5:00	L
150	1:20	8	10:00	L
160	1:20	12	14:00	L
170	1:20	16	18:00	L
180	1:20	20	22:00
190	1:20	24	26:00
200	1:20	27	29:00
210	1:20	31	33:00
220	1:20	34	36:00
230	1:20	37	39:00
240	1:20	40	42:00
250	1:20	42	44:00
260	1:20	45	47:00
270	1:20	47	49:00
280	1:20	49	51:00
290	1:20	51	53:00
300	1:20	53	55:00
310	1:20	55	57:00
320	1:20	57	59:00
330	1:20	59	61:00
340	1:20	61	63:00
350	1:20	64	66:00
360	1:20	66	68:00

70 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	20 ft	Total Ascent (M:S)	Rep Group
86	2:20	0	2:20	M
90	1:40	3	5:20	M
95	1:40	8	10:20
100	1:40	12	14:20
110	1:40	19	21:20
120	1:40	26	28:20
130	1:40	33	35:20
140	1:40	39	41:20
150	1:40	45	47:20
160	1:40	50	52:20
170	1:40	55	57:20
180	1:40	60	62:20
190	1:40	64	66:20
200	1:40	68	70:20
210	1:40	72	74:20
220	1:40	76	78:20

80 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	20 ft	Total Ascent (M:S)	Rep Group
63	2:40	0	2:40	M
65	2:00	2	4:40	M
70	2:00	8	10:40
75	2:00	14	16:40
80	2:00	19	21:40
85	2:00	24	26:40
90	2:00	29	31:40
95	2:00	34	36:40
100	2:00	39	41:40
110	2:00	48	50:40
120	2:00	56	58:40
130	2:00	63	65:40
140	2:00	70	72:40
150	2:00	76	78:40
160	2:00	82	84:40
170	2:00	88	90:40
180	2:00	93	95:40
190	2:00	98	100:40

90 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	20 ft	Total Ascent (M:S)	Rep Group
44	3:00	0	3:00	K
45	2:20	1	4:00	K
50	2:20	2	5:00	L
55	2:20	7	10:00	M
60	2:20	15	18:00
65	2:20	22	25:00
70	2:20	29	32:00
75	2:20	35	38:00
80	2:20	41	44:00
85	2:20	47	50:00
90	2:20	53	56:00
95	2:20	58	61:00
100	2:20	63	66:00
110	2:20	73	76:00
120	2:20	82	85:00
130	2:20	90	93:00
140	2:20	97	100:00
150	2:20	105	108:00
160	2:20	112	115:00

100 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	30 ft	20 ft	Total Ascent (M:S)	Rep Group
31	3:20		0	3:20	J
35	2:40		2	5:20	K
40	2:40		4	7:20	L
45	2:40		6	9:20	M
50	2:40		16	19:20
55	2:40		24	27:20
60	2:40		33	36:20
65	2:40		41	44:20
70	2:40		48	51:20
75	2:40		55	58:20
80	2:40		62	65:20
85	2:40		68	71:20
90	2:40		74	77:20
95	2:40		80	83:20
100	2:40		85	88:20
110	2:40		96	99:20
120	2:40		105	108:20
130	2:20	1	114	118:00
140	2:20	1	124	128:00

110 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	40 ft	30 ft	20 ft	Total Ascent (M:S)	Rep Group
24	3:40			0	3:40	I
25	3:00			1	4:40	I
30	3:00			4	7:40	J
35	3:00			7	10:40	L
40	3:00			10	13:40	M
45	3:00			21	24:40
50	3:00			31	34:40
55	3:00			40	43:40
60	2:40		1	49	53:20
65	2:40		2	57	62:20
70	2:40		3	64	70:20
75	2:40		4	71	78:20
80	2:40		5	77	85:20
85	2:40		5	84	92:20
90	2:40		6	89	98:20
95	2:40		6	95	104:20
100	2:40		6	101	110:20
110	2:40		7	112	122:20
EXCEPTIONAL EXPOSURE
120	2:40		7	123	133:20
130	2:40		7	136	146:20
140	2:20	1	7	149	160:00

120 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	40 ft	30 ft	20 ft	Total Ascent (M:S)	Rep Group
20	4:00			0	4:00	I
25	3:20			4	8:00	J
30	3:20			8	12:00	K
35	3:20			12	16:00	M
40	3:20			23	27:00
45	3:00		2	34	39:40
50	3:00		4	43	50:40
55	3:00		6	52	61:40
60	3:00		7	60	70:40
65	2:40	2	7	68	80:20
70	2:40	3	7	76	89:20
75	2:40	3	8	83	97:20
80	2:40	4	7	91	105:20
85	2:40	5	7	97	112:20
90	2:40	5	8	103	119:20
95	2:40	6	7	110	126:20
EXCEPTIONAL EXPOSURE
100	2:40	6	7	117	133:20
110	2:40	7	7	131	148:20
120	2:40	7	7	145	162:20

130 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	50 ft	40 ft	30 ft	20 ft	Total Ascent (M:S)	Rep Group
17	4:20				0	4:20	H
20	3:40				3	7:20	I
25	3:40				8	12:20	K
30	3:40				13	17:20	L
35	3:20			2	21	27:00	L
40	3:20			5	32	41:00	L
45	3:00		1	7	43	54:40	L
50	3:00		3	7	53	66:40
55	3:00		5	7	63	78:40
60	3:00		6	8	71	88:40
65	2:40	1	7	7	81	99:20
70	2:40	2	7	7	89	108:20
75	2:40	3	7	7	97	117:20
80	2:40	3	8	7	104	125:20
85	2:40	4	8	7	111	133:20
EXCEPTIONAL EXPOSURE
90	2:40	5	7	7	119	141:20
95	2:40	5	8	7	127	150:20
100	2:40	6	7	7	136	159:20
110	2:40	6	8	7	152	176:20
120	2:40	7	7	18	159	194:20

140 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	60 ft	50 ft	40 ft	30 ft	20 ft	Total Ascent (M:S)	Rep Group
15	4:40					0	4:40	H
20	4:00					7	11:40	J
25	4:00					12	16:40	K
30	3:40				3	16	23:20	M
35	3:40				7	29	40:20
40	3:20			3	7	42	56:00
45	3:20			6	7	53	70:00
50	3:00		1	8	7	64	83:40
55	3:00		3	8	7	74	95:40
60	3:00		5	8	7	84	107:40
65	3:00		7	7	7	93	117:40
70	2:40	1	7	8	7	101	127:20
75	2:40	2	7	8	7	110	137:20
EXCEPTIONAL EXPOSURE
80	2:40	3	7	8	7	118	146:20
85	2:40	4	7	7	8	127	156:20
90	2:40	4	8	7	7	137	166:20
95	2:40	5	7	7	8	146	176:20
100	2:40	5	8	7	8	155	186:20

150 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Total Ascent (M:S)	Rep Group
13	5:00						0	5:00	H
15	4:20						3	8:00	H
20	4:20						10	15:00	J
25	4:00					2	14	20:40	L
30	4:00					7	24	35:40	L
35	3:40				4	8	37	53:20	L
40	3:20			1	7	8	50	70:00
45	3:20			4	8	7	63	86:00
50	3:20			7	7	8	74	100:00
55	3:00		2	8	7	7	86	113:40
60	3:00		4	8	7	7	96	125:40
65	3:00		6	7	7	8	105	136:40
70	3:00		7	7	8	7	114	146:40
EXCEPTIONAL EXPOSURE
75	2:40	1	8	7	7	8	124	158:20
80	2:40	2	8	7	7	8	135	170:20
85	2:40	3	7	8	7	7	146	181:20
90	2:40	4	7	7	8	9	155	193:20

160 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Total Ascent (M:S)	Rep Group
12	5:20							0	5:20	H
15	4:40							5	10:20	I
20	4:40							13	18:20	K
25	4:20						6	16	27:00	M
30	4:00					4	8	31	47:40
35	3:40				2	7	8	46	67:20
40	3:40				6	8	7	60	85:20
45	3:20			3	7	7	8	73	102:00
50	3:20			6	7	7	8	85	117:00
55	3:00		1	7	8	7	7	97	130:40
60	3:00		3	7	8	7	8	107	143:40
EXCEPTIONAL EXPOSURE
65	3:00		5	7	8	7	7	118	155:40
70	3:00		6	8	7	7	8	130	169:40
75	3:00		8	7	7	8	7	142	182:40
80	2:40	2	7	7	8	7	7	154	195:20
85	2:40	2	8	7	8	7	16	158	209:20
90	2:40	3	8	7	7	8	25	161	222:20

170 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	100 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Total Ascent (M:S)	Rep Group
11	5:40								0	5:40	H
15	5:00								8	13:40	I
20	4:40							2	15	22:20	K
25	4:20						2	8	22	37:00	L
30	4:00					2	7	7	39	59:40	L
35	4:00					7	7	8	55	81:40
40	3:40				4	8	7	7	70	100:20
45	3:20			1	7	8	7	7	84	118:00
50	3:20			4	7	8	7	8	96	134:00
55	3:20			7	7	7	8	7	108	148:00
EXCEPTIONAL EXPOSURE
60	3:00		2	7	8	7	7	8	120	162:40
65	3:00		4	7	8	7	7	8	134	178:40
70	3:00		5	8	7	8	7	7	148	193:40
75	3:00		7	7	8	7	7	12	157	208:40
80	2:40	1	7	8	7	7	8	22	160	223:20

180 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Total Ascent (M:S)	Rep Group
10	6:00								0	6:00	H
15	5:20								11	17:00	J
20	5:00							6	14	25:40	L
25	4:40						6	8	29	48:20	L
30	4:20					6	7	8	47	73:00
35	4:00				4	8	7	8	64	95:40
40	3:40			2	8	7	7	8	80	116:20
45	3:40			6	8	7	7	8	94	134:20
50	3:20		3	7	7	8	7	7	108	151:00
EXCEPTIONAL EXPOSURE
55	3:20		5	8	7	8	7	7	121	167:00
60	3:00	1	7	8	7	7	8	7	136	184:40
65	3:00	3	7	8	7	7	8	7	151	201:40
70	3:00	5	7	7	8	7	7	16	158	218:40

190 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	120 ft	110 ft	100 ft	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Total Ascent (M:S)	Rep Group
9	6:20											0	6:20	H
10	5:40											2	8:20	H
15	5:40											14	20:20	J
20	4:40								1	1	8	16	31:20	M
25	3:20				1	0	0	0	4	7	7	38	61:00
30	3:00			1	0	0	2	2	7	7	8	57	87:40
35	2:40		1	0	0	2	0	8	7	8	7	75	111:20
40	2:20	1	0	0	0	2	6	8	7	7	8	91	133:00
45	2:20	1	0	0	0	5	7	8	7	7	8	105	151:00
50	2:20	1	0	0	0	8	8	7	8	7	7	120	169:00
EXCEPTIONAL EXPOSURE
55	2:20	1	0	0	4	8	7	7	8	7	7	138	190:00
60	2:20	1	0	0	7	7	8	7	7	8	7	153	208:00
65	2:20	1	0	2	7	7	8	7	7	8	19	159	228:00
70	2:20	1	0	3	8	7	8	7	7	8	31	164	247:00

200 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	170 ft	160 ft	150 ft	140 ft	130 ft	120 ft	110 ft	100 ft	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Total Ascent (M:S)	Rep Group
8	6:40																0	6:40	G
10	6:00																5	11:40	H
15	5:20														1	1	15	23:00	K
20	3:20								1	0	0	2	0	0	5	7	25	44:00	L
25	2:00				1	0	0	0	2	0	1	0	1	7	7	7	47	75:40	L
30	1:20		1	0	0	2	0	0	0	2	0	1	7	7	8	7	69	106:00
35	1:20		1	0	1	1	0	0	2	0	0	7	7	7	8	7	87	130:00
40	1:00	1	0	1	1	0	0	2	0	0	5	8	7	7	8	7	104	152:40
45	1:00	1	0	1	1	0	0	2	0	2	7	8	7	8	7	7	120	172:40
EXCEPTIONAL EXPOSURE
50	1:00	1	0	1	1	0	1	0	1	6	7	7	8	7	8	7	139	195:40
55	1:00	1	0	1	1	0	1	0	2	8	7	7	8	7	8	8	155	215:40
60	1:00	1	0	1	1	0	1	0	5	7	8	7	7	8	7	22	161	237:40

210 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	120 ft	110 ft	100 ft	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Total Ascent (M:S)
5	7:00											0	7:00
10	6:20											5	12:00
15	6:00										7	5	18:40
20	5:00							5	3	2	2	28	45:40
25	4:20					3	3	3	2	3	3	57	79:00
30	4:20					6	3	2	2	6	12	76	112:00
35	3:40			3	3	3	2	3	5	12	12	95	142:20
40	3:20		3	2	3	2	3	5	12	11	12	113	170:00
EXCEPTIONAL EXPOSURE
45	3:20		4	2	3	2	4	11	12	12	11	131	196:00
50	3:20		4	3	2	3	10	11	12	12	11	149	221:00
55	3:00	3	2	3	2	7	11	11	12	11	12	165	242:40
60	3:20		5	3	2	11	12	11	11	12	21	173	265:00

220 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	110 ft	100 ft	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Total Ascent (M:S)
5	7:20										0	7:20
10	6:40										5	12:20
15	5:40							4	3	2	6	21:20
20	5:00					4	3	2	3	2	37	56:40
25	5:00					7	3	3	2	8	65	93:40
30	4:00		3	3	2	3	3	3	10	12	84	127:40
35	4:20			8	2	3	2	12	12	11	106	161:00
40	4:20			9	3	2	12	11	12	11	126	191:00
EXCEPTIONAL EXPOSURE
45	3:40	6	2	3	2	10	12	11	12	11	144	217:20
50	4:00		8	3	8	11	12	11	11	12	164	244:40
55	4:00		9	4	12	11	12	11	11	18	177	269:40

230 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	140 ft	130 ft	120 ft	110 ft	100 ft	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Total Ascent (M:S)
5	7:40													0	7:40
10	7:00													6	13:40
15	6:00										5	3	2	9	25:40
20	5:00							3	3	2	3	3	2	46	67:40
25	4:40						5	2	3	3	2	3	12	71	106:20
30	4:00				3	3	2	3	2	3	6	12	12	93	143:40
35	4:00				5	3	2	3	2	8	12	12	11	116	178:40
EXCEPTIONAL EXPOSURE
40	3:20		2	3	2	3	2	3	8	12	11	12	11	137	210:00
45	4:00				8	2	3	7	12	11	11	12	11	159	240:40
50	3:20		4	3	2	3	5	11	13	11	11	11	16	174	268:00
55	3:00	2	3	2	4	2	12	11	11	11	11	11	38	172	293:40

240 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	130 ft	120 ft	110 ft	100 ft	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Total Ascent (M:S)
5	8:00												0	8:00
10	7:20												8	16:00
15	6:00								4	3	2	4	15	34:40
20	5:20						5	2	3	2	3	3	54	78:00
25	5:20						9	3	2	2	8	12	80	122:00
30	4:20			5	3	2	2	3	3	11	12	12	103	161:00
35	4:20			7	3	2	3	4	12	11	12	12	127	198:00
EXCEPTIONAL EXPOSURE
40	4:20			8	3	3	4	12	12	11	12	12	150	232:00
45	4:20			10	2	4	12	12	11	12	11	12	173	264:00
50	3:40	6	3	2	3	12	11	11	12	11	11	32	174	292:20

250 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	140 ft	130 ft	120 ft	110 ft	100 ft	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Total Ascent (M:S)
5	8:20													0	8:20
10	7:40													9	17:20
15	6:20									5	3	3	2	24	44:00
20	5:40							6	3	2	3	3	6	61	90:20
25	5:00					6	3	2	2	3	3	12	12	87	135:40
30	4:20			4	3	3	2	3	2	8	11	12	12	112	177:00
EXCEPTIONAL EXPOSURE
35	4:40				9	2	3	2	10	12	12	11	12	139	217:20
40	4:20			8	3	2	3	11	12	11	11	12	11	164	253:00
45	4:00		7	3	3	2	11	11	12	11	11	12	25	175	287:40
50	3:40	6	2	3	3	9	12	11	11	12	11	11	49	175	319:20

260 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	140 ft	130 ft	120 ft	110 ft	100 ft	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Total Ascent (M:S)
5	8:40													0	8:40
10	8:00													11	19:40
15	6:20								4	3	3	2	3	31	53:00
20	5:40						5	3	3	2	3	3	10	67	102:20
25	5:20					8	3	2	2	3	7	13	12	96	152:00
30	4:40			6	3	2	3	2	3	12	12	13	11	123	195:20
EXCEPTIONAL EXPOSURE
35	4:40			8	3	3	2	6	12	12	11	12	11	151	236:20
40	4:20		8	3	2	3	7	12	12	11	11	12	14	175	275:00
45	4:00	7	3	2	3	8	12	11	11	11	12	11	42	173	310:40

270 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	140 ft	130 ft	120 ft	110 ft	100 ft	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Total Ascent (M:S)
5	8:20													5	14:00
10	8:20													13	22:00
15	6:20							3	3	3	2	3	3	39	63:00
20	6:20							9	3	2	3	5	12	75	116:00
25	5:40					9	3	2	3	3	12	11	12	105	166:20
EXCEPTIONAL EXPOSURE
30	5:00			8	3	2	3	2	9	11	12	11	12	134	212:40
35	4:40		8	3	2	3	3	11	12	12	11	11	12	163	256:20
40	4:20	8	3	3	1	5	12	12	11	11	11	12	30	174	298:00
45	4:20	9	3	2	5	12	13	10	11	11	12	11	56	176	336:00

280 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	140 ft	130 ft	120 ft	110 ft	100 ft	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Total Ascent (M:S)
5	8:40													5	14:20
10	8:40													14	23:20
15	7:00								7	3	2	3	3	47	72:40
20	6:20						9	2	3	2	3	9	12	82	129:00
25	5:20			6	3	3	2	3	2	7	12	12	12	114	182:00
EXCEPTIONAL EXPOSURE
30	5:20			10	3	2	3	3	12	12	11	12	12	145	231:00
35	4:40	8	2	3	2	3	8	12	12	11	11	11	13	176	277:20
40	4:40	10	2	3	2	11	12	11	12	12	10	12	45	174	321:20
45	4:40	11	3	3	11	11	12	11	11	11	12	11	72	178	362:20

290 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	140 ft	130 ft	120 ft	110 ft	100 ft	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Total Ascent (M:S)
5	9:00													5	14:40
10	8:00										4	4	2	6	24:40
15	7:00							6	3	2	3	3	2	55	81:40
20	6:20					8	2	3	2	3	4	12	12	88	141:00
25	5:40			8	3	2	3	3	2	12	12	11	12	122	196:20
EXCEPTIONAL EXPOSURE
30	5:00	7	3	2	3	3	2	9	12	12	11	11	12	156	248:40
35	5:00	10	2	3	2	5	12	11	12	11	11	12	28	176	300:40
40	5:00	12	2	3	7	12	11	12	11	11	11	12	59	177	345:40
45	5:00	13	3	9	11	12	11	11	11	11	11	18	82	180	388:40

300 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	140 ft	130 ft	120 ft	110 ft	100 ft	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Total Ascent (M:S)
5	9:20													5	15:00
10	8:20										6	3	2	9	29:00
15	7:00						5	3	2	3	2	3	5	61	91:40
20	6:20				7	3	2	3	2	4	6	12	12	96	154:00
25	5:20	5	3	2	3	3	2	3	7	12	11	12	11	132	212:00
EXCEPTIONAL EXPOSURE
30	5:20	9	3	2	3	2	5	12	12	11	11	12	12	169	269:00
35	5:20	12	2	3	2	10	12	11	12	11	11	12	41	176	321:00
40	5:20	14	2	4	12	12	11	11	12	11	11	11	74	180	371:00

310 FSW

All schedules at this depth are Exceptional Exposure.

Bottom Time (min)	Time to 1st Stop (M:S)	140 ft	130 ft	120 ft	110 ft	100 ft	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Total Ascent (M:S)
10	8:20									5	2	3	3	14	36:00
15	7:20						6	3	3	2	3	2	9	66	102:00
20	6:20			6	3	2	3	2	3	3	12	11	12	103	167:00
25	6:00		9	3	2	3	3	2	12	11	12	12	11	142	228:40
30	5:40	11	3	2	2	3	10	12	11	11	12	12	17	176	288:20
35	5:40	14	2	3	6	12	11	12	11	11	11	12	55	178	344:20
40	5:40	16	2	10	12	11	12	11	11	11	11	19	83	182	397:20

320 FSW

All schedules at this depth are Exceptional Exposure.

Bottom Time (min)	Time to 1st Stop (M:S)	140 ft	130 ft	120 ft	110 ft	100 ft	90 ft	80 ft	70 ft	60 ft	50 ft	40 ft	30 ft	20 ft	Total Ascent (M:S)
10	8:20								4	2	3	3	2	21	44:00
15	7:40						8	3	2	3	2	3	12	71	112:20
20	6:20		6	2	3	2	3	2	4	5	12	12	12	111	181:00
25	6:20		11	3	2	2	3	7	12	11	12	11	12	153	246:00
30	6:00	13	2	3	2	6	12	11	12	11	11	12	30	177	308:40
35	6:00	15	3	3	11	12	11	12	11	11	11	12	68	182	368:40
40	6:00	18	7	11	12	11	11	11	12	11	11	35	83	185	424:40

MK 16 MOD 1 Closed-Circuit UBA Tables (0.75 ata ppO2)

(DESCENT RATE 60 FPM — ASCENT RATE 30 FPM)

The following tables apply to the MK 16 MOD 1 closed-circuit underwater breathing apparatus operating at a constant partial pressure of oxygen of 0.75 ata.

Table 15-14. No-Decompression Limits and Repetitive Group Designators for 0.75 ata ppO2 N2O2 Dives

Notes:

– Diver does not acquire a repetitive group designator during dives to these depths
* Highest repetitive group that can be achieved at this depth regardless of bottom time
Blank cells = Group not achievable at this depth
Depths at 160 FSW and deeper are Exceptional Exposure (require CO authorization)

Depth (fsw)	No-Stop Limit	A	B	C	D	E	F	G	H	I	J	K	L	M	N	O	Z
10	Unlimited	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–
15	Unlimited	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–
20	Unlimited	154	425	*
30	Unlimited	31	50	73	98	128	165	211	274	375	643	*
40	369	17	27	38	50	63	76	91	107	125	144	167	192	223	259	305	369
50	143	12	19	26	33	41	50	59	68	78	88	99	111	123	137	143
60	74	9	14	19	25	31	37	43	50	56	63	71	74
70	51	7	11	15	20	25	29	34	39	44	50	51
80	40	6	9	13	16	20	24	28	32	36	40
90	32	5	8	11	14	17	20	24	27	31	32
100	27	4	7	9	12	15	18	21	24	27
110	23	3	6	8	11	13	16	18	21	23
120	20	3	5	7	9	12	14	16	18	20
130	16		4	6	8	10	12	14	16
140	14		4	6	7	9	11	13	14
150	11		3	5	7	8	10	11
Exceptional Exposure
160	10		3	4	6	8	9	10
170	9		3	4	5	7	8	9

Table 15-15. Residual Nitrogen Timetable for Repetitive 0.75 ata Constant ppO2 N2O2 Dives

Part 1: Surface Interval Credit Table

Note: The Surface Interval Credit intervals for 0.75 ata ppO2 N2O2 are identical to those for Air (Table 9-8 Part 1), since both use the same nitrogen offgassing model.

Locate the diver’s repetitive group designation from his previous dive in the left column. Read horizontally to the interval in which the diver’s surface interval lies. Read vertically downward to the new repetitive group designation.

Previous Group	Z	O	N	M	L	K	J	I	H	G	F	E	D	C	B	A	Not Rep (>)
Z	0:10–0:52	0:53–1:44	1:45–2:37	2:38–3:29	3:30–4:21	4:22–5:13	5:14–6:06	6:07–6:58	6:59–7:50	7:51–8:42	8:43–9:34	9:35–10:27	10:28–11:19	11:20–12:13	12:14–13:30	13:31–15:50	15:50
O		0:10–0:52	0:53–1:44	1:45–2:37	2:38–3:29	3:30–4:21	4:22–5:13	5:14–6:06	6:07–6:58	6:59–7:50	7:51–8:42	8:43–9:34	9:35–10:27	10:28–11:21	11:22–12:37	12:38–14:58	14:58
N			0:10–0:52	0:53–1:44	1:45–2:37	2:38–3:29	3:30–4:21	4:22–5:13	5:14–6:06	6:07–6:58	6:59–7:50	7:51–8:42	8:43–9:34	9:35–10:29	10:30–11:45	11:46–14:05	14:05
M				0:10–0:52	0:53–1:44	1:45–2:37	2:38–3:29	3:30–4:21	4:22–5:13	5:14–6:06	6:07–6:58	6:59–7:50	7:51–8:42	8:43–9:37	9:38–10:53	10:54–13:13	13:13
L					0:10–0:52	0:53–1:44	1:45–2:37	2:38–3:29	3:30–4:21	4:22–5:13	5:14–6:06	6:07–6:58	6:59–7:50	7:51–8:44	8:45–10:01	10:02–12:21	12:21
K						0:10–0:52	0:53–1:44	1:45–2:37	2:38–3:29	3:30–4:21	4:22–5:13	5:14–6:06	6:07–6:58	6:59–7:52	7:53–9:09	9:10–11:29	11:29
J							0:10–0:52	0:53–1:44	1:45–2:37	2:38–3:29	3:30–4:21	4:22–5:13	5:14–6:06	6:07–7:00	7:01–8:16	8:17–10:36	10:36
I								0:10–0:52	0:53–1:44	1:45–2:37	2:38–3:29	3:30–4:21	4:22–5:13	5:14–6:08	6:09–7:24	7:25–9:44	9:44
H									0:10–0:52	0:53–1:44	1:45–2:37	2:38–3:29	3:30–4:21	4:22–5:16	5:17–6:32	6:33–8:52	8:52
G										0:10–0:52	0:53–1:44	1:45–2:37	2:38–3:29	3:30–4:23	4:24–5:40	5:41–8:00	8:00
F											0:10–0:52	0:53–1:44	1:45–2:37	2:38–3:31	3:32–4:48	4:49–7:08	7:08
E												0:10–0:52	0:53–1:44	1:45–2:39	2:40–3:55	3:56–6:15	6:15
D													0:10–0:52	0:53–1:47	1:48–3:03	3:04–5:23	5:23
C														0:10–0:55	0:56–2:11	2:12–4:31	4:31
B															0:10–1:16	1:17–3:36	3:36
A																0:10–2:20	2:20

* Dives following surface intervals longer than the “Not Rep” time are not repetitive dives. Use actual bottom times in Tables 15-14 and 15-16 to compute decompression for such dives.

Part 2: Residual Nitrogen Times (Minutes)

Using the new repetitive group designation from Part 1, read down the column to the row representing the depth of the repetitive dive. The time at the intersection is the Residual Nitrogen Time (RNT) in minutes to be applied to the repetitive dive.

Depth (fsw)	Z	O	N	M	L	K	J	I	H	G	F	E	D	C	B	A
10	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–
15	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–
20	**	**	**	**	**	**	**	**	**	**	**	**	**	**	420	153
30	**	**	**	**	**	**	626	372	273	211	165	129	99	73	51	31
40	365	303	258	222	192	167	144	125	107	91	77	63	51	39	28	18
50	167	151	137	123	111	99	88	78	68	59	50	42	34	27	19	12
60	113	104	95	87	79	71	64	57	50	44	38	32	26	20	15	10
70	86	79	73	67	61	56	50	45	40	35	30	25	21	16	12	8
80	69	64	60	55	50	46	41	37	33	29	25	21	18	14	10	7
90	58	54	50	46	43	39	35	32	28	25	22	18	15	12	9	6
100	50	47	44	40	37	34	31	28	25	22	19	16	13	11	8	5
110	44	41	38	36	33	30	27	25	22	19	17	14	12	9	7	5
120	39	37	34	32	29	27	25	22	20	18	15	13	11	9	6	4
130	36	33	31	29	27	24	22	20	18	16	14	12	10	8	6	4
140	33	30	28	26	24	22	20	18	17	15	13	11	9	7	5	4
150	30	28	26	24	22	21	19	17	15	14	12	10	8	7	5	3
160	28	26	24	23	21	19	18	16	14	13	11	9	8	6	5	3
170	26	24	23	21	19	18	16	15	13	12	10	9	7	6	4	3

Notes

– Repetitive dives to these depths are equivalent to remaining on the surface. Add the bottom time of the dive to the preceding surface interval. Use the Surface Interval Credit Table (SICT) to determine the repetitive group at the end of the dive.
** Residual Nitrogen Time cannot be determined using this table. See paragraph 9-9.1 subparagraph 8 for guidance. Substitute the ** depths in this table for those in the instructions.

Table 15-16. 0.75 ata ppO2 N2O2 Decompression Tables

(DESCENT RATE 60 FPM — ASCENT RATE 30 FPM)

Stop times (min) include travel time, except first stop.

40 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	10	Total Ascent (M:S)	Rep Group
369	1:20	0	1:20	Z
370	1:00	1	2:20	Z
380	1:00	2	3:20	Z
390	1:00	3	4:20	Z

50 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	10	Total Ascent (M:S)	Rep Group
143	1:40	0	1:40	O
150	1:20	3	4:40	O
160	1:20	8	9:40	O
170	1:20	12	13:40	O
180	1:20	15	16:40	Z
190	1:20	19	20:40	Z
200	1:20	22	23:40	Z
210	1:20	25	26:40	Z
220	1:20	29	30:40	Z
230	1:20	33	34:40	Z
240	1:20	37	38:40	Z
250	1:20	42	43:40	Z
260	1:20	45	46:40	Z
270	1:20	49	50:40	Z
280	1:20	52	53:40	Z
290	1:20	56	57:40	Z
300	1:20	59	60:40	Z
310	1:20	61	62:40	Z
320	1:20	64	65:40	Z
330	1:20	67	68:40	Z
Exceptional Exposure
340	1:20	69	70:40
350	1:20	73	74:40
360	1:20	77	78:40
370	1:20	80	81:40
380	1:20	83	84:40
390	1:20	87	88:40

60 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	20	10	Total Ascent (M:S)	Rep Group
74	2:00		0	2:00	L
75	1:40		1	3:00	L
80	1:40		3	5:00	L
90	1:40		8	10:00	M
100	1:40		12	14:00	N
110	1:40		16	18:00	O
120	1:40		24	26:00	O
130	1:40		32	34:00	O
140	1:40		38	40:00	Z
150	1:40		44	46:00	Z
160	1:40		50	52:00	Z
170	1:40		55	57:00	Z
180	1:20	3	60	64:40	Z
190	1:20	8	62	71:40	Z
200	1:20	12	65	78:40	Z
210	1:20	15	69	85:40	Z
220	1:20	19	71	91:40	Z
230	1:20	22	74	97:40	Z
240	1:20	25	76	102:40	Z
250	1:20	27	80	108:40	Z
Exceptional Exposure
260	1:20	30	82	113:40
270	1:20	32	85	118:40
280	1:20	35	88	124:40
290	1:20	40	90	131:40
300	1:20	43	93	137:40
310	1:20	47	94	142:40
320	1:20	51	96	148:40
330	1:20	54	98	153:40
340	1:20	57	100	158:40
350	1:20	60	102	163:40
360	1:20	63	105	169:40
370	1:20	65	109	175:40
380	1:20	68	112	181:40
390	1:20	70	115	186:40

70 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	30	20	10	Total Ascent (M:S)	Rep Group
51	2:20			0	2:20	K
55	2:00			4	6:20	K
60	2:00			9	11:20	K
70	2:00			17	19:20	L
80	2:00			24	26:20	M
90	1:40		2	29	33:00	N
100	1:40		7	34	43:00	O
110	1:40		12	39	53:00	O
120	1:40		15	46	63:00	O
130	1:40		18	52	72:00	Z
140	1:40		21	57	80:00	Z
150	1:40		29	58	89:00	Z
160	1:40		36	62	100:00	Z
170	1:40		42	66	110:00	Z
180	1:40		48	70	120:00	Z
Exceptional Exposure
190	1:20	1	53	73	128:40
200	1:20	2	57	77	137:40
210	1:20	6	57	81	145:40
220	1:20	10	57	84	152:40
230	1:20	14	59	87	161:40
240	1:20	18	62	89	170:40
250	1:20	21	66	91	179:40
260	1:20	24	69	94	188:40
270	1:20	26	72	97	196:40
280	1:20	29	75	99	204:40
290	1:20	31	78	102	212:40
300	1:20	33	81	105	220:40
310	1:20	35	83	110	229:40
320	1:20	37	86	113	237:40
330	1:20	41	86	118	246:40
340	1:20	45	86	124	256:40
350	1:20	49	88	127	265:40

80 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	40	30	20	10	Total Ascent (M:S)	Rep Group
40	2:40				0	2:40	J
45	2:20				8	10:40	K
50	2:20				15	17:40	K
55	2:20				21	23:40	L
60	2:20				27	29:40	L
70	2:00			9	28	39:20	M
80	2:00			17	29	48:20	N
90	2:00			24	36	62:20	O
100	1:40		2	29	43	76:00	O
110	1:40		7	29	50	88:00	Z
120	1:40		12	29	57	100:00	Z
Exceptional Exposure
130	1:40		15	37	58	112:00
140	1:40		18	43	62	125:00
150	1:40		21	49	67	139:00
160	1:40		23	56	70	151:00
170	1:40		29	57	75	163:00
180	1:40		36	57	80	175:00
190	1:40		42	57	85	186:00
200	1:20	1	48	60	86	196:40
210	1:20	2	52	64	90	209:40
220	1:20	2	57	68	93	221:40
230	1:20	6	57	73	96	233:40
240	1:20	10	57	77	100	245:40
250	1:20	14	57	81	104	257:40
260	1:20	18	56	85	110	270:40
270	1:20	21	59	86	116	283:40
280	1:20	24	63	85	124	297:40
290	1:20	26	67	86	129	309:40
300	1:20	29	70	88	134	322:40
310	1:20	31	73	92	137	334:40
320	1:20	33	76	95	141	346:40

90 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	40	30	20	10	Total Ascent (M:S)	Rep Group
32	3:00				0	3:00	J
35	2:40				5	8:00	J
40	2:40				14	17:00	K
45	2:40				23	26:00	K
50	2:20			3	28	33:40	L
55	2:20			10	28	40:40	L
60	2:20			17	28	47:40	M
70	2:20			28	29	59:40	N
80	2:00		10	29	34	75:20	O
90	2:00		18	29	44	93:20	Z
Exceptional Exposure
100	2:00		25	29	52	108:20
110	1:40	3	29	33	56	123:00
120	1:40	8	29	41	62	142:00
130	1:40	12	29	49	67	159:00
140	1:40	16	29	56	73	176:00
150	1:40	19	36	57	76	190:00
160	1:40	21	43	57	81	204:00
170	1:40	23	50	57	89	221:00
180	1:40	25	56	62	91	236:00
190	1:40	31	57	67	95	252:00

100 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	40	30	20	10	Total Ascent (M:S)	Rep Group
27	3:20				0	3:20	I
30	3:00				6	9:20	J
35	3:00				18	21:20	J
40	3:00				28	31:20	K
45	2:40			10	28	41:00	L
50	2:40			19	28	50:00	M
55	2:40			27	29	59:00	M
60	2:20		7	28	28	65:40	N
65	2:20		14	28	28	72:40	O
Exceptional Exposure
70	2:20		20	28	32	82:40
75	2:20		26	28	37	93:40
80	2:00	3	28	29	42	104:20
90	2:00	12	29	28	53	124:20
100	2:00	20	29	34	61	146:20
110	2:00	27	28	44	66	167:20

110 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	50	40	30	20	10	Total Ascent (M:S)	Rep Group
23	3:40					0	3:40	I
25	3:20					4	7:40	J
30	3:20					18	21:40	J
35	3:00				3	28	34:20	K
40	3:00				14	29	46:20	L
45	3:00				25	29	57:20	L
50	2:40			7	29	28	67:00	M
55	2:40			16	29	28	76:00	N
Exceptional Exposure
60	2:40			25	28	29	85:00
65	2:20		4	29	28	33	96:40
70	2:20		11	29	28	40	110:40
80	2:20		24	28	29	52	135:40
90	2:00	6	29	28	34	65	164:20

120 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	50	40	30	20	10	Total Ascent (M:S)	Rep Group
20	4:00					0	4:00	I
25	3:40					14	18:00	J
30	3:20				3	27	33:40	J
35	3:20				15	29	47:40	K
40	3:00			4	25	28	60:20	L
45	3:00			12	29	28	72:20	M
Exceptional Exposure
50	2:40		1	23	28	28	83:00
55	2:40		5	29	28	29	94:00
60	2:40		15	28	28	35	109:00
70	2:20	3	28	29	28	50	140:40
80	2:20	17	28	29	31	68	175:40

130 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	50	40	30	20	10	Total Ascent (M:S)	Rep Group
16	4:20					0	4:20	H
20	4:00					5	9:20	I
25	3:40				4	20	28:00	J
30	3:20			2	11	28	44:40	K
35	3:20			7	21	29	60:40	L
Exceptional Exposure
40	3:00		1	14	28	28	74:20
45	3:00		7	21	28	29	88:20
50	3:00		12	28	28	29	100:20
55	2:40	3	20	28	29	34	117:00
60	2:40	7	26	28	29	43	136:00
70	2:40	23	28	28	29	67	178:00

140 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	60	50	40	30	20	10	Total Ascent (M:S)	Rep Group
14	4:40						0	4:40	H
15	4:20						1	5:40	H
20	4:00					3	11	18:20	J
25	3:40				3	7	24	38:00	K
30	3:20			1	7	17	28	56:40	L
Exceptional Exposure
35	3:20			4	13	24	29	73:40
40	3:20			11	18	28	28	88:40
45	3:00		4	14	25	29	28	103:20
50	3:00		10	18	28	29	35	123:20
60	2:40	5	18	28	29	28	61	172:00
70	2:40	14	28	29	28	36	80	218:00

150 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	70	60	50	40	30	20	10	Total Ascent (M:S)	Rep Group
11	5:00							0	5:00	G
15	4:40							6	11:00	H
20	4:00					2	7	14	27:20	J
25	3:40				2	7	9	27	49:00	K
30	3:40				7	9	20	28	68:00	M
Exceptional Exposure
35	3:20			3	10	14	28	28	86:40
40	3:20			7	14	22	28	29	103:40
45	3:00		1	14	15	29	28	35	125:20
50	3:00		7	14	23	29	28	49	153:20
60	2:40	3	14	24	29	28	32	76	209:00
70	2:40	10	24	28	29	28	52	91	265:00

160 FSW

All bottom times are Exceptional Exposure.

Bottom Time (min)	Time to 1st Stop (M:S)	70	60	50	40	30	20	10	Total Ascent (M:S)
10	5:20							0	5:20
15	4:40						3	7	15:00
20	4:20					6	8	17	35:40
25	4:00				7	7	12	29	59:20
30	3:40			6	7	12	23	28	80:00
35	3:20		3	7	12	17	29	28	99:40
40	3:20		5	13	14	25	29	35	124:40
45	3:20		12	14	19	29	28	49	154:40
50	3:00	4	15	14	28	28	29	65	186:20

170 FSW

All bottom times are Exceptional Exposure.

Bottom Time (min)	Time to 1st Stop (M:S)	80	70	60	50	40	30	20	10	Total Ascent (M:S)
9	5:40								0	5:40
10	5:20								2	7:40
15	4:40						2	6	7	20:00
20	4:20					5	7	7	21	44:40
25	4:00				6	7	7	17	28	69:20
30	3:40			5	7	8	14	26	29	93:00
35	3:20		2	7	9	14	21	28	35	119:40
40	3:20		5	9	14	15	28	29	46	149:40
45	3:20		8	15	14	24	28	29	65	186:40
50	3:00	2	14	14	19	28	29	36	76	221:20

Table 15-17. 0.75 ata ppO2 HeO2 Decompression Tables

(DESCENT RATE 60 FPM — ASCENT RATE 30 FPM)

Stop times (min) include travel time, except first stop.

40 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	10	Total Ascent (M:S)	Rep Group
390	1:20	0	1:20

50 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	10	Total Ascent (M:S)
205	1:40	0	1:40
210	1:20	3	4:40
220	1:20	9	10:40
230	1:20	14	15:40
240	1:20	20	21:40
250	1:20	24	25:40
Exceptional Exposure
260	1:20	29	30:40
270	1:20	33	34:40
280	1:20	37	38:40
290	1:20	41	42:40
300	1:20	45	46:40
310	1:20	48	49:40
320	1:20	52	53:40
330	1:20	55	56:40
340	1:20	58	59:40
350	1:20	60	61:40
360	1:20	63	64:40
370	1:20	65	66:40
380	1:20	68	69:40
390	1:20	70	71:40

60 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	20	10	Total Ascent (M:S)
133	2:00		0	2:00
140	1:40		8	10:00
150	1:40		20	22:00
160	1:40		30	32:00
170	1:40		40	42:00
Exceptional Exposure
180	1:40		50	52:00
190	1:40		59	61:00
200	1:40		67	69:00
210	1:40		75	77:00
220	1:40		82	84:00
230	1:40		90	92:00
240	1:40		96	98:00
250	1:40		103	105:00
260	1:40		109	111:00
270	1:20	1	113	115:40
280	1:20	7	113	121:40
290	1:20	12	113	126:40
300	1:20	16	114	131:40
310	1:20	21	113	135:40
320	1:20	25	113	139:40
330	1:20	29	113	143:40
340	1:20	33	113	147:40
350	1:20	36	113	150:40
360	1:20	40	113	154:40
370	1:20	43	113	157:40
380	1:20	46	113	160:40
390	1:20	49	113	163:40

70 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	20	10	Total Ascent (M:S)
82	2:20		0	2:20
85	2:00		2	4:20
90	2:00		6	8:20
95	2:00		9	11:20
100	2:00		12	14:20
110	2:00		19	21:20
120	2:00		35	37:20
130	2:00		51	53:20
140	2:00		65	67:20
Exceptional Exposure
150	2:00		79	81:20
160	2:00		92	94:20
170	2:00		104	106:20
180	1:40	7	109	118:00
190	1:40	14	113	129:00
200	1:40	24	113	139:00
210	1:40	34	113	149:00
220	1:40	43	113	158:00
230	1:40	52	113	167:00
240	1:40	60	113	175:00
250	1:40	68	113	183:00
260	1:40	75	113	190:00
270	1:40	82	113	197:00

80 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	20	10	Total Ascent (M:S)
52	2:40		0	2:40
55	2:20		2	4:40
60	2:20		5	7:40
65	2:20		8	10:40
70	2:20		14	16:40
75	2:20		19	21:40
80	2:20		24	26:40
85	2:20		29	31:40
90	2:20		33	35:40
95	2:20		36	38:40
100	2:00	3	44	49:20
110	2:00	9	58	69:20
120	2:00	14	73	89:20
Exceptional Exposure
130	2:00	18	87	107:20
140	2:00	22	100	124:20
150	2:00	33	105	140:20
160	2:00	43	111	156:20
170	2:00	55	113	170:20
180	2:00	69	113	184:20
190	2:00	82	113	197:20

90 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	30	20	10	Total Ascent (M:S)
37	3:00			0	3:00
40	2:40			4	7:00
45	2:40			10	13:00
50	2:40			15	18:00
55	2:40			19	22:00
60	2:20		1	23	26:40
65	2:20		4	27	33:40
70	2:20		6	32	40:40
75	2:20		8	36	46:40
80	2:20		12	38	52:40
85	2:20		17	38	57:40
90	2:20		22	44	68:40
95	2:20		26	53	81:40
100	2:20		30	61	93:40
110	2:20		38	77	117:40
120	2:00	6	38	94	140:20
Exceptional Exposure
130	2:00	11	46	102	161:20
140	2:00	15	55	109	181:20
150	2:00	19	66	113	200:20
160	2:00	22	81	113	218:20

100 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	40	30	20	10	Total Ascent (M:S)
29	3:20				0	3:20
30	3:00				1	4:20
35	3:00				11	14:20
40	3:00				19	22:20
50	2:40			9	22	34:00
60	2:40			18	27	48:00
70	2:20		2	22	38	64:40
80	2:20		7	31	41	81:40
90	2:20		11	38	59	110:40
100	2:20		21	38	78	139:40
Exceptional Exposure
110	2:20		29	39	96	166:40
120	2:20		36	50	103	191:40
130	2:00	4	38	61	111	216:20
140	2:00	9	38	76	113	238:20

110 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	50	40	30	20	10	Total Ascent (M:S)
23	3:40					0	3:40
25	3:20					2	5:40
30	3:20					14	17:40
35	3:00				3	22	28:20
40	3:00				11	22	36:20
50	2:40			3	22	22	50:00
60	2:40			13	22	33	71:00
70	2:40			20	28	37	88:00
80	2:20		3	23	37	55	120:40
90	2:20		7	31	38	76	154:40
100	2:20		11	38	39	96	186:40
Exceptional Exposure
110	2:20		20	38	52	103	215:40
120	2:20		28	38	64	111	243:40
130	2:20		34	40	80	113	269:40
140	2:00	2	38	51	89	113	295:20

120 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	50	40	30	20	10	Total Ascent (M:S)
18	4:00					0	4:00
20	3:40					2	6:00
25	3:40					13	17:00
30	3:20				5	22	30:40
35	3:20				16	22	41:40
40	3:00			4	22	22	51:20
50	3:00			19	23	24	69:20
60	2:40		9	22	22	37	93:00
70	2:40		16	22	34	52	127:00
80	2:40		22	29	38	72	164:00
Exceptional Exposure
90	2:20	4	24	37	38	95	200:40
100	2:20	7	32	38	50	104	233:40
110	2:20	12	37	38	65	112	266:40
120	2:20	20	38	41	83	113	297:40

130 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	60	50	40	30	20	10	Total Ascent (M:S)
15	4:20						0	4:20
20	4:00						8	12:20
25	3:40					6	18	28:00
30	3:20				2	16	22	43:40
35	3:20				8	22	22	55:40
40	3:20				19	22	22	66:40
50	3:00			14	22	22	28	89:20
60	2:40		4	22	22	26	48	125:00
70	2:40		12	22	24	38	70	169:00
Exceptional Exposure
80	2:40		18	22	36	38	93	210:00
90	2:20	1	22	32	37	46	107	247:40
100	2:20	4	26	38	37	64	113	284:40
110	2:20	6	35	38	40	84	113	318:40
120	2:20	12	38	38	55	93	113	351:40

140 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	70	60	50	40	30	20	10	Total Ascent (M:S)
12	4:40							0	4:40
15	4:20							4	8:40
20	4:00						5	12	21:20
25	3:40					4	10	22	40:00
30	3:40					10	20	22	56:00
35	3:20				4	18	22	22	69:40
40	3:20				12	22	22	22	81:40
50	3:00			8	22	22	22	35	112:20
60	3:00			21	22	22	31	66	165:20
70	2:40		9	22	22	29	38	93	216:00
Exceptional Exposure
80	2:40		15	22	27	38	40	113	258:00
90	2:40		20	23	38	38	63	113	298:00
100	2:20	1	22	35	38	37	88	113	336:40

150 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	70	60	50	40	30	20	10	Total Ascent (M:S)
10	5:00							0	5:00
15	4:20						2	7	13:40
20	4:00					2	10	15	31:20
25	3:40				2	9	15	22	52:00
30	3:40				7	14	22	22	69:00
35	3:20			3	11	22	22	22	83:40
40	3:20			6	21	22	22	22	96:40
45	3:20			15	22	22	22	33	117:40
50	3:00		2	23	22	22	22	56	150:20
55	3:00		10	22	22	22	27	74	180:20
60	3:00		16	22	23	22	35	88	209:20
Exceptional Exposure
70	2:40	5	22	22	22	35	40	113	262:00
80	2:40	12	22	22	34	38	65	113	309:00
90	2:40	17	22	31	38	38	90	113	352:00

155 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	80	70	60	50	40	30	20	10	Total Ascent (M:S)
9	5:10								0	5:10
10	4:50								1	6:10
15	4:30							3	9	16:50
20	4:10						5	10	17	36:30
25	3:50					5	9	17	22	57:10
30	3:30				2	9	17	22	22	75:50
35	3:30				6	15	22	22	22	90:50
40	3:30				12	22	22	22	22	103:50
45	3:10			3	20	22	22	22	44	136:30
50	3:10			10	23	22	22	22	68	170:30
55	3:10			18	22	22	22	30	84	201:30
60	2:50		3	22	22	22	22	38	100	232:10
Exceptional Exposure
70	2:50		14	22	22	22	38	52	113	286:10
80	2:50		21	22	22	38	37	77	113	333:10
90	2:30	5	22	22	35	38	37	103	113	377:50

160 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	80	70	60	50	40	30	20	10	Total Ascent (M:S)
9	5:20								0	5:20
10	5:00								2	7:20
15	4:20						1	4	10	19:40
20	4:00					1	8	9	19	41:20
25	4:00					8	10	19	22	63:20
30	3:40				5	10	19	22	22	82:00
35	3:20			1	9	18	22	22	22	97:40
40	3:20			4	15	22	22	23	27	116:40
45	3:20			9	22	22	22	22	55	155:40
50	3:20			18	22	23	22	22	79	189:40
Exceptional Exposure
55	3:00		5	22	22	22	22	31	97	224:20
60	3:00		12	22	22	22	24	38	113	256:20
70	2:40	1	22	22	22	25	38	64	113	310:00
80	2:40	8	22	23	25	37	38	91	113	360:00
90	2:40	14	22	24	37	38	43	111	113	405:00

165 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	80	70	60	50	40	30	20	10	Total Ascent (M:S)
8	5:30								0	5:30
10	5:10								3	8:30
15	4:30						2	6	9	21:50
20	4:10					2	10	9	21	46:30
25	3:50				2	10	9	22	22	69:10
30	3:50				9	9	22	22	22	88:10
35	3:30			5	9	21	22	22	22	104:50
40	3:30			8	19	22	22	22	39	135:50
45	3:10		1	16	22	22	22	22	66	174:30
50	3:10		5	22	22	22	22	24	92	212:30
Exceptional Exposure
55	3:10		13	22	22	22	22	34	108	246:30
60	3:10		20	22	22	22	27	48	113	277:30
70	2:50	10	22	22	22	28	38	79	113	337:10
80	2:50	18	22	22	28	38	38	105	113	387:10

170 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	90	80	70	60	50	40	30	20	10	Total Ascent (M:S)
8	5:40									0	5:40
10	5:00								1	3	9:20
15	4:40							4	7	9	25:00
20	4:20						5	10	10	22	51:40
25	4:00					6	9	11	22	22	74:20
30	3:40				3	10	12	22	22	22	95:00
35	3:40				8	12	22	22	22	22	112:00
40	3:20			3	9	22	22	22	22	50	153:40
45	3:20			5	19	22	23	22	22	78	194:40
50	3:20			13	22	22	22	22	26	104	234:40
Exceptional Exposure
55	3:20			21	23	22	22	22	42	113	268:40
60	3:00		7	22	22	22	22	29	62	113	302:20
70	3:00		19	22	22	22	31	38	92	113	362:20
80	2:40	5	22	22	22	32	38	43	113	113	413:00

175 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	90	80	70	60	50	40	30	20	10	Total Ascent (M:S)
7	5:50									0	5:50
10	5:10								2	4	11:30
15	4:30						1	4	8	10	27:50
20	4:10					1	7	10	12	22	56:30
25	4:10					9	9	14	22	22	80:30
30	3:50				7	9	15	22	22	22	101:10
35	3:30			3	9	15	22	22	22	31	127:50
40	3:30			7	13	22	22	22	22	62	173:50
Exceptional Exposure
45	3:30			10	22	22	22	22	22	91	214:50
50	3:10		2	19	22	22	22	22	30	113	255:30
55	3:10		8	22	22	22	22	22	58	113	292:30
60	3:10		16	22	22	22	22	31	76	113	327:30
65	3:10		22	22	22	22	25	38	90	113	357:30
70	2:50	6	22	22	22	22	34	38	106	113	388:10
75	2:50	10	22	22	23	27	37	45	113	113	415:10
80	2:50	14	22	22	22	36	38	58	113	113	441:10

180 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	90	80	70	60	50	40	30	20	10	Total Ascent (M:S)
7	6:00									0	6:00
10	5:20								3	4	12:40
15	4:40						3	4	9	11	32:00
20	4:20					3	8	10	14	22	61:40
25	4:00				3	9	10	16	22	22	86:20
30	3:40			1	10	9	17	22	22	23	108:00
35	3:40			7	9	17	22	23	22	41	145:00
40	3:20		1	10	16	22	22	22	22	73	191:40
Exceptional Exposure
45	3:20		4	14	22	22	22	22	22	105	236:40
50	3:20		7	22	22	22	22	22	44	113	277:40
55	3:20		16	22	22	22	22	24	70	113	314:40
60	3:00	3	22	22	22	22	22	33	90	113	352:20
65	3:00	9	22	22	22	22	28	38	105	113	384:20
70	3:00	15	22	22	22	22	37	45	113	113	414:20

185 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	100	90	80	70	60	50	40	30	20	10	Total Ascent (M:S)
6	6:10										0	6:10
10	5:30									4	4	13:50
15	4:50							4	5	10	12	36:10
20	4:10					1	4	10	9	16	22	66:30
25	4:10					6	10	9	19	22	22	92:30
30	3:50				5	9	10	20	22	22	22	114:10
35	3:30			1	10	9	21	22	22	22	52	162:50
40	3:30			5	10	19	22	22	22	22	86	211:50
Exceptional Exposure
45	3:30			8	18	22	22	22	22	28	113	258:50
50	3:10		1	14	22	22	22	22	22	58	113	299:30
55	3:10		3	22	22	22	22	22	26	84	113	339:30
60	3:10		11	22	22	22	22	22	36	103	113	376:30
65	3:10		18	22	22	22	22	30	44	113	113	409:30
70	2:50	2	22	22	22	22	24	38	60	113	113	441:10

190 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	100	90	80	70	60	50	40	30	20	10	Total Ascent (M:S)
6	6:20										0	6:20
10	5:20								1	4	5	15:40
15	4:40						2	4	6	9	15	41:00
20	4:20					2	6	10	9	18	22	71:40
25	4:00				1	9	9	10	20	23	22	98:20
30	4:00				8	10	10	22	22	22	27	125:20
35	3:40			5	9	11	22	22	22	22	63	180:00
40	3:40			9	11	22	22	22	22	22	99	233:00
Exceptional Exposure
45	3:20		3	9	22	22	22	22	22	41	113	279:40
50	3:20		5	18	22	22	22	22	22	73	113	322:40
55	3:20		11	22	22	22	22	22	28	99	113	364:40
60	3:20		20	22	22	22	22	22	42	114	113	402:40
65	3:00	5	22	22	22	22	22	33	59	113	113	436:20
70	3:00	11	22	22	22	22	27	38	76	113	113	469:20

195 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	100	90	80	70	60	50	40	30	20	10	Total Ascent (M:S)
6	6:30										0	6:30
10	5:30								3	3	6	17:50
15	4:50						3	4	8	9	16	45:10
20	4:30					4	7	10	9	20	22	76:50
25	4:10				4	9	10	10	22	22	22	103:30
30	3:50			3	9	10	12	22	23	22	37	142:10
35	3:50			9	9	14	22	22	22	22	75	199:10
40	3:30		4	9	14	22	22	22	22	22	112	252:50
Exceptional Exposure
45	3:30		7	12	22	22	22	22	22	55	113	300:50
50	3:30		9	22	22	22	22	22	22	88	113	345:50
55	3:10	1	19	22	22	22	22	22	30	113	113	389:30
60	3:10	6	22	22	22	22	22	26	55	113	113	426:30

200 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	100	90	80	70	60	50	40	30	20	10	Total Ascent (M:S)
6	6:40										0	6:40
10	5:40								4	4	6	20:00
15	4:40					1	4	4	8	10	17	49:00
20	4:20				2	4	9	9	9	22	22	81:40
25	4:20				7	10	9	13	22	22	22	109:40
30	4:00			6	10	9	16	22	22	22	48	159:20
35	3:40		3	10	9	17	22	22	22	22	87	218:00
Exceptional Exposure
40	3:40		7	10	17	22	22	22	22	34	113	273:00
45	3:20	1	10	16	22	22	22	22	22	70	113	323:40
50	3:20	4	14	22	22	22	22	22	22	106	113	372:40
55	3:20	6	22	22	22	22	22	22	46	113	113	413:40
60	3:20	15	22	22	22	22	22	27	72	113	114	454:40

205 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	110	100	90	80	70	60	50	40	30	20	10	Total Ascent (M:S)
5	6:50											0	6:50
10	5:30								1	4	4	8	22:50
15	4:50						2	4	5	9	9	19	53:10
20	4:30					3	5	9	10	11	22	22	86:50
25	4:10				2	9	9	10	15	22	22	22	115:30
30	3:50			1	9	10	9	18	22	22	22	59	176:10
35	3:50			7	9	10	20	22	22	22	22	100	238:10
Exceptional Exposure
40	3:30		2	10	9	21	22	22	22	22	48	113	294:50
45	3:30		5	10	20	22	22	22	22	22	85	113	346:50
50	3:30		8	18	22	22	22	22	22	30	113	113	395:50
55	3:30		14	22	22	22	22	22	22	62	113	113	437:50
60	3:10	2	22	22	22	22	22	22	30	87	113	113	480:30

210 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	110	100	90	80	70	60	50	40	30	20	10	Total Ascent (M:S)
5	7:00											0	7:00
10	5:40								2	4	4	9	25:00
15	5:00						4	3	6	10	9	20	57:20
20	4:20				1	4	6	10	9	13	22	22	91:40
25	4:20				5	9	9	10	17	22	22	26	124:40
30	4:00			4	10	9	9	21	22	23	22	68	192:20
35	3:40		1	10	9	11	22	22	22	22	22	112	257:00
Exceptional Exposure
40	3:40		6	9	12	22	22	22	22	22	61	113	315:00
45	3:40		9	11	22	23	22	22	22	22	100	113	370:00
50	3:20	2	10	22	22	22	22	22	22	45	113	113	418:40
55	3:20	4	19	22	22	22	22	22	22	81	113	113	465:40
60	3:20	10	22	22	22	22	22	22	32	103	113	113	506:40

215 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	110	100	90	80	70	60	50	40	30	20	10	Total Ascent (M:S)
5	7:10											0	7:10
10	5:50								3	4	4	10	27:10
15	4:50					1	4	4	7	9	10	22	62:10
20	4:30				2	4	8	10	9	15	22	22	96:50
25	4:10			1	7	10	9	9	20	22	22	36	140:30
30	4:10			8	9	10	11	22	22	22	22	81	211:30
Exceptional Exposure
35	3:50		5	10	9	14	22	22	22	22	35	113	278:10
40	3:30	1	9	10	15	22	22	22	22	22	77	113	338:50
45	3:30	4	9	15	22	22	22	23	22	24	113	113	392:50
50	3:30	6	14	22	22	22	22	22	22	62	113	114	444:50
55	3:30	9	22	22	22	22	22	22	23	97	113	113	490:50
60	3:30	19	22	22	22	22	22	22	41	112	113	113	533:50

220 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	120	110	100	90	80	70	60	50	40	30	20	10	Total Ascent (M:S)
5	7:20												0	7:20
10	5:40								1	4	4	5	9	29:00
15	5:00						3	3	4	9	9	11	22	66:20
20	4:40					4	4	9	10	9	17	22	22	102:00
25	4:20				3	8	10	9	10	22	22	22	45	155:40
30	4:00			2	10	9	9	14	22	22	22	22	93	229:20
Exceptional Exposure
35	4:00			9	9	10	17	22	22	22	22	48	113	298:20
40	3:40		5	9	9	19	22	22	22	22	22	92	113	361:00
45	3:40		8	9	19	22	22	22	22	22	41	113	113	417:00
50	3:20	1	10	17	22	22	22	22	22	22	80	113	113	469:40
55	3:20	3	15	22	22	22	22	22	22	30	108	113	113	517:40

225 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	120	110	100	90	80	70	60	50	40	30	20	10	Total Ascent (M:S)
4	7:30												0	7:30
5	7:10												1	8:30
10	5:50								2	4	4	6	9	31:10
15	5:10						4	4	4	9	10	12	22	70:30
20	4:30				2	4	5	10	9	9	19	22	22	106:50
25	4:10			1	5	9	9	10	12	22	22	22	56	172:30
30	4:10			6	9	9	10	16	22	22	23	22	104	247:30
Exceptional Exposure
35	3:50		3	10	9	10	20	22	22	22	22	61	113	318:10
40	3:50		8	10	9	22	22	22	22	22	22	106	113	382:10
45	3:30	3	9	10	22	22	22	22	22	22	56	113	113	439:50
50	3:30	5	10	21	22	22	22	22	22	22	97	113	113	494:50
55	3:30	7	19	22	22	22	22	22	22	42	113	113	114	543:50

230 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	130	120	110	100	90	80	70	60	50	40	30	20	10	Total Ascent (M:S)
4	7:40													0	7:40
5	7:20													2	9:40
10	6:00									3	4	4	7	9	33:20
15	5:00						2	4	3	6	9	9	14	22	74:20
20	4:40					3	4	7	9	10	9	21	22	22	112:00
25	4:20				2	7	9	10	9	14	22	22	22	66	187:40
30	4:20				9	10	9	9	20	22	22	22	26	113	266:40
Exceptional Exposure
35	4:00			7	9	10	10	22	22	22	22	22	74	113	337:20
40	3:40		3	9	10	13	22	22	22	22	22	31	113	113	406:00
45	3:40		7	9	14	22	22	22	22	22	22	74	113	113	466:00
50	3:40		9	13	22	22	22	22	22	22	27	109	113	113	520:00
55	3:20	2	10	22	22	22	23	22	22	22	60	113	113	113	569:40

235 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	130	120	110	100	90	80	70	60	50	40	30	20	10	Total Ascent (M:S)
4	7:50													0	7:50
5	7:30													3	10:50
10	5:50								1	4	3	4	8	10	36:10
15	5:10						3	4	4	6	10	9	15	22	78:30
20	4:30				1	4	4	8	10	9	10	22	22	22	116:50
25	4:30				4	8	9	10	9	17	22	22	22	76	203:50
30	4:10			4	9	9	10	9	22	22	22	22	38	113	284:30
Exceptional Exposure
35	3:50		2	9	9	10	13	22	22	23	22	22	88	113	359:10
40	3:50		7	9	10	16	22	22	22	22	22	46	113	113	428:10
45	3:30	1	10	9	17	23	22	22	22	22	22	90	113	113	489:50
50	3:30	4	9	17	22	22	22	22	22	22	40	113	113	113	544:50

240 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	130	120	110	100	90	80	70	60	50	40	30	20	10	Total Ascent (M:S)
4	8:00													0	8:00
5	7:40													3	11:00
10	6:00								2	4	4	3	9	10	38:20
15	5:00					1	4	4	3	8	9	10	17	22	83:20
20	4:40				3	3	5	9	10	9	12	22	22	32	132:00
25	4:20			2	4	10	9	9	10	19	22	22	22	87	220:40
Exceptional Exposure
30	4:20			7	9	10	9	12	22	22	22	22	51	113	303:40
35	4:00		5	10	9	10	16	22	22	22	22	22	104	113	381:20
40	3:40	1	10	9	10	19	22	22	22	22	22	60	113	113	449:00
45	3:40	5	10	9	21	22	22	22	22	22	22	107	113	113	514:00
50	3:40	8	9	21	22	22	22	22	22	22	58	113	113	113	571:00

245 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	140	130	120	110	100	90	80	70	60	50	40	30	20	10	Total Ascent (M:S)
5	7:30													1	4	12:50
10	6:10									3	4	4	4	9	11	41:30
15	5:10						2	4	4	4	9	9	9	19	22	87:30
20	4:50					4	4	6	9	10	9	14	22	22	41	146:10
25	4:30				3	6	10	9	10	9	21	22	22	22	98	236:50
Exceptional Exposure
30	4:10			1	10	9	10	9	15	22	22	22	22	64	113	323:30
35	4:10			9	9	10	9	20	22	22	22	22	27	113	113	402:30
40	3:50		5	10	9	11	22	22	22	22	22	22	77	114	113	475:10
45	3:50		9	10	12	22	22	22	22	22	22	33	113	113	113	539:10
50	3:30	3	9	12	22	22	22	22	22	23	22	75	113	114	113	597:50

250 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	140	130	120	110	100	90	80	70	60	50	40	30	20	10	Total Ascent (M:S)
5	7:40													1	4	13:00
10	6:20									4	4	4	5	9	12	44:40
15	5:20						3	4	4	5	9	9	10	20	22	91:40
20	4:40				2	4	4	7	9	10	9	16	22	22	50	160:00
25	4:20			1	4	8	9	10	9	11	22	22	22	22	110	254:40
Exceptional Exposure
30	4:20			5	9	10	9	10	17	22	22	22	22	78	113	343:40
35	4:00		4	9	9	10	10	22	22	22	22	22	41	113	114	424:20
40	4:00		9	9	10	14	22	22	22	22	22	22	94	113	113	498:20
45	3:40	4	9	10	16	22	22	22	22	22	22	51	113	113	113	565:00
50	3:40	7	9	16	22	22	22	22	22	22	22	95	113	113	113	624:00

255 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	150	140	130	120	110	100	90	80	70	60	50	40	30	20	10	Total Ascent (M:S)
5	7:50														2	4	14:10
10	6:10									1	4	4	4	6	10	12	47:30
15	5:10						1	4	4	4	5	10	9	10	22	22	96:30
20	4:50					3	4	4	9	9	10	9	18	22	22	59	174:10
25	4:30				3	4	9	10	9	10	13	22	22	22	31	113	272:50
Exceptional Exposure
30	4:10			1	8	9	10	9	9	21	22	22	22	22	91	113	363:30
35	4:10			7	10	9	9	14	22	22	22	22	22	56	113	113	445:30
40	3:50		4	9	10	9	17	22	22	22	22	22	25	107	113	113	521:10
45	3:50		8	9	10	19	22	22	22	22	22	22	68	113	113	113	589:10
50	3:30	2	9	10	20	22	22	22	22	22	22	32	104	113	113	113	651:50

260 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	150	140	130	120	110	100	90	80	70	60	50	40	30	20	10	Total Ascent (M:S)
5	8:00														3	4	15:20
10	6:20									2	4	4	4	7	10	14	51:40
15	5:20						2	4	4	4	7	9	10	11	22	22	100:40
20	4:40				1	4	4	5	9	10	9	9	20	22	22	69	189:00
25	4:20			1	4	5	10	9	10	9	16	22	22	22	43	113	290:40
Exceptional Exposure
30	4:20			3	9	10	9	9	11	22	22	22	22	22	105	113	383:40
35	4:00		2	9	10	9	9	17	22	22	22	22	22	72	113	113	468:20
40	4:00		8	9	9	10	20	22	22	23	22	22	34	113	113	113	544:20
45	3:40	3	9	9	11	22	22	22	22	22	22	22	86	113	113	113	615:00

265 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	150	140	130	120	110	100	90	80	70	60	50	40	30	20	10	Total Ascent (M:S)
5	8:10														4	4	16:30
10	6:30									4	3	4	4	8	10	15	54:50
15	5:30						4	4	3	4	9	9	9	13	22	22	104:50
20	4:50				3	4	3	7	9	10	9	9	22	22	22	78	203:10
25	4:30			2	4	8	9	10	9	9	18	22	22	22	55	113	307:50
Exceptional Exposure
30	4:30			6	10	9	9	10	13	22	22	22	22	27	113	113	402:50
35	4:10		5	10	9	10	9	19	22	23	22	22	22	87	113	113	490:30
40	3:50	2	10	9	10	11	22	22	22	22	22	22	52	113	113	113	569:10
45	3:50	7	9	9	15	22	22	22	22	22	22	26	100	113	113	113	641:10

270 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	160	150	140	130	120	110	100	90	80	70	60	50	40	30	20	10	Total Ascent (M:S)
5	8:00														1	4	4	17:20
10	6:20									1	4	4	4	4	9	9	16	57:40
15	5:20						1	4	4	4	4	9	10	9	15	22	22	109:40
20	5:00					4	4	4	8	9	9	10	11	22	22	22	88	218:20
25	4:40				4	4	9	9	10	9	10	20	22	22	22	66	113	325:00
Exceptional Exposure
30	4:20			2	8	9	10	9	10	16	22	22	22	22	41	113	113	423:40
35	4:20			9	9	10	9	10	22	22	22	22	22	22	102	113	113	511:40
40	4:00		6	9	10	9	15	22	22	22	22	22	22	69	113	113	113	593:20
45	3:40	1	10	9	10	18	22	22	22	22	22	22	37	107	113	113	113	667:00

275 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	160	150	140	130	120	110	100	90	80	70	60	50	40	30	20	10	Total Ascent (M:S)
5	8:10														2	4	4	18:30
10	6:30									2	4	4	4	4	10	9	18	61:50
15	5:30						3	4	3	4	5	10	9	10	16	22	24	115:50
20	4:50				2	4	4	4	9	9	10	9	14	22	22	22	99	235:10
Exceptional Exposure
25	4:30			2	4	5	9	10	9	10	10	22	22	22	22	79	113	343:50
30	4:30			4	9	10	9	10	9	19	22	22	22	22	55	113	113	443:50
35	4:10		4	9	9	10	9	13	22	22	22	22	22	32	108	113	113	534:30
40	3:50	1	9	10	9	9	19	22	22	22	22	22	22	86	113	113	114	619:10
45	3:50	5	10	9	9	22	22	22	22	22	22	22	48	113	113	113	113	691:10

280 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	160	150	140	130	120	110	100	90	80	70	60	50	40	30	20	10	Total Ascent (M:S)
5	8:20														3	4	3	18:40
10	6:40									3	4	4	4	5	10	9	19	65:00
15	5:40						4	4	4	4	6	9	10	9	18	22	32	128:00
20	5:00				3	4	4	5	10	9	10	9	15	23	22	22	109	250:20
Exceptional Exposure
25	4:40			3	4	7	10	9	10	9	12	22	22	22	22	92	113	362:00
30	4:20		2	6	9	10	9	10	9	21	22	22	22	22	70	113	113	464:40
35	4:20		7	10	9	9	10	16	22	22	22	22	22	43	113	113	113	557:40
40	4:00	4	10	9	10	9	22	22	22	22	22	22	26	99	113	113	113	642:20
45	4:00	9	9	10	13	22	22	22	22	22	22	22	68	113	113	113	113	719:20

285 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	170	160	150	140	130	120	110	100	90	80	70	60	50	40	30	20	10	Total Ascent (M:S)
5	8:30															3	4	4	19:50
10	6:30									1	4	4	3	4	7	9	10	20	68:50
15	5:30						2	4	4	3	4	8	9	10	9	21	22	40	141:50
20	4:50				1	4	4	4	7	9	9	10	9	18	22	22	29	113	266:10
Exceptional Exposure
25	4:30			1	4	4	9	9	10	9	10	14	22	22	22	23	104	113	380:50
30	4:30			3	8	10	9	10	9	11	22	22	22	22	22	84	113	113	484:50
35	4:10		2	9	10	9	9	10	19	22	22	22	22	22	59	113	113	113	580:30
40	4:10		8	10	9	10	12	22	22	22	22	22	22	38	104	113	113	113	666:30
45	3:50	4	9	10	9	17	22	22	22	22	22	22	22	87	113	113	113	113	746:10

290 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	170	160	150	140	130	120	110	100	90	80	70	60	50	40	30	20	10	Total Ascent (M:S)
5	8:20														1	4	3	5	21:40
10	6:40									2	4	4	4	3	8	9	10	22	73:00
15	5:40						3	4	4	4	4	8	10	9	10	22	22	48	154:00
20	5:00				3	4	3	4	9	9	9	10	9	20	22	22	40	113	282:20
Exceptional Exposure
25	4:40			3	4	5	9	9	10	9	10	17	22	22	22	31	109	113	400:00
30	4:20		1	5	9	10	9	9	10	14	22	22	22	22	23	99	113	113	507:40
35	4:20		5	10	9	10	9	10	22	22	22	22	22	22	76	113	113	113	604:40
40	4:00	3	9	10	9	10	15	22	23	22	22	22	22	49	111	113	113	113	692:20
45	4:00	8	9	10	9	20	22	22	22	22	22	22	31	95	113	113	113	113	770:20

295 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	180	170	160	150	140	130	120	110	100	90	80	70	60	50	40	30	20	10	Total Ascent (M:S)
5	8:30														1	4	4	5	22:50
10	6:50										3	4	4	4	3	9	9	11	22	76:10
15	5:30						1	4	4	3	4	5	9	10	9	12	22	22	56	166:50
20	4:50				1	3	4	4	4	10	9	10	9	10	22	22	22	50	113	298:10
Exceptional Exposure
25	4:30			1	4	4	6	10	9	9	10	9	20	22	22	22	41	112	113	418:50
30	4:30			3	6	10	9	9	10	9	17	22	22	22	22	33	103	113	113	527:50
35	4:30			9	9	10	9	10	12	22	22	22	22	22	23	91	113	113	113	626:50
40	4:10		7	9	10	9	9	20	22	22	22	22	22	22	66	113	113	113	113	718:30
45	3:50	2	10	9	10	11	22	22	22	22	22	22	22	43	102	113	113	113	113	797:10

300 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	180	170	160	150	140	130	120	110	100	90	80	70	60	50	40	30	20	10	Total Ascent (M:S)
5	8:40															2	4	4	6	25:00
10	7:00										4	4	4	4	4	9	9	12	22	79:20
15	5:40						2	4	4	4	4	5	10	9	10	14	22	22	64	180:00
20	5:00				2	4	4	4	5	10	9	10	9	12	22	22	22	62	113	315:20
Exceptional Exposure
25	4:40			2	4	4	8	10	9	10	9	9	22	22	23	22	51	113	113	436:00
30	4:20		1	4	8	9	10	9	10	9	20	22	22	22	22	43	108	113	113	549:40
35	4:20		4	9	9	10	9	10	15	22	22	22	22	23	32	97	113	113	113	649:40
40	4:00	1	10	9	10	9	10	22	22	22	22	22	22	22	83	113	113	113	113	742:20

310 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	180	170	160	150	140	130	120	110	100	90	80	70	60	50	40	30	20	10	Total Ascent (M:S)
Exceptional Exposure
6	8:20													1	4	4	4	6	9	36:40
10	7:00									2	4	4	4	4	6	9	10	15	22	87:20
15	5:40					1	4	4	4	4	4	8	9	9	10	18	22	22	81	206:00
20	5:00			1	4	4	4	4	8	10	9	10	9	17	22	22	22	85	113	349:20
25	4:40		2	4	3	7	9	10	9	9	10	14	22	22	22	22	81	113	113	477:00
30	4:40		4	6	10	9	10	9	10	12	22	22	22	22	22	69	113	113	113	593:00
35	4:20	2	9	10	9	9	10	9	22	22	22	22	22	22	54	109	113	113	113	696:40
40	4:20	9	9	10	9	10	16	22	22	22	22	23	22	41	98	113	113	113	113	791:40

320 FSW

Bottom Time (min)	Time to 1st Stop (M:S)	190	180	170	160	150	140	130	120	110	100	90	80	70	60	50	40	30	20	10	Total Ascent (M:S)
Exceptional Exposure
6	8:40														3	4	4	4	7	10	41:00
10	7:00									1	4	4	4	4	4	7	10	9	19	22	95:20
15	6:00						4	3	4	4	4	5	10	9	9	10	22	22	22	98	232:20
20	5:20				4	4	4	4	6	9	10	9	9	10	22	22	22	28	102	113	383:40
25	4:40		1	4	4	4	9	10	9	10	9	10	19	22	22	22	34	96	113	113	516:00
30	4:40		3	5	10	9	9	10	9	10	18	22	22	22	22	31	91	113	113	113	637:00
35	4:20	1	8	10	9	10	9	9	16	22	22	22	22	22	24	84	113	113	113	113	746:40
40	4:20	7	10	9	10	9	11	22	22	22	22	22	22	22	66	112	113	113	113	113	844:40

Frequently Asked Questions

Why use helium-oxygen instead of air at depth?

Air causes nitrogen narcosis at depths beyond ~100 FSW (individual variation), which impairs diver judgment and performance. Helium does not cause narcosis, making HeO2 the preferred gas for deep operations. HeO2 also has faster decompression kinetics than air at equivalent depths due to helium’s lower solubility.

What are the gas switch requirements?

USN Table 12-4 mandates specific gas switches during ascent:

Bottom mix (HeO2) — all bottom time and stops at 50 FSW and deeper
50% O2 — stop at 40 FSW
100% O2 — stops at 30 and 20 FSW

These switches are non-optional and dramatically reduce total decompression time.

What does “Chamber O2 Periods” mean?

Each chamber O2 period is 30 minutes of 100% oxygen breathing in a deck recompression chamber (DRC) after surfacing. This surface decompression (SurDO2) completes the decompression obligation started in the water. The number of periods required increases with bottom time and depth.

USN Air Dive Tables — Air decompression tables with interactive NDL lookup
USN Dive Tables Overview — Complete index of all USN tables
Surface-Supplied Diving Systems
Dive Planning & Risk Assessment
Emergency Response Frameworks

Depth (fsw)	Z	O	N	M	L	K	J	I	H	G	F	E	D	C	B	A
10	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–
15	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–
20	**	**	**	**	**	**	**	**	**	**	**	**	**	**	420	153
25	**	**	**	**	**	**	**	**	**	**	556	296	196	134	88	51
30	**	**	**	**	**	**	626	372	273	211	165	129	99	73	51	31
35	**	**	671	423	325	263	218	181	152	126	104	84	67	51	36	22
40	**	**	**	**	**	**	**	**	**	**	**	**	**	311	166	88
50	**	**	**	**	**	481	339	262	209	168	135	107	84	63	44	27
60	293	252	220	192	168	148	129	112	97	83	70	58	46	36	26	16
70	153	139	126	114	103	92	82	73	64	56	47	40	32	25	18	12
80	107	98	90	82	75	68	61	54	48	42	36	30	25	19	14	9
90	82	76	70	64	59	54	48	43	38	34	29	25	20	16	12	8
100	67	62	58	53	49	44	40	36	32	28	24	21	17	13	10	7
110	57	53	49	45	41	38	34	31	28	24	21	18	15	12	9	6
120	49	46	42	39	36	33	30	27	24	21	19	16	13	10	8	5
130	43	40	38	35	32	29	27	24	22	19	17	14	12	9	7	5
140	39	36	34	31	29	26	24	22	19	17	15	13	11	8	6	4
150	35	33	31	28	26	24	22	20	18	16	14	12	10	8	6	4
160	32	30	28	26	24	22	20	18	16	14	13	11	9	7	5	4
170	30	28	26	24	22	20	19	17	15	13	12	10	8	7	5	3
180	27	26	24	22	21	19	17	16	14	12	11	9	8	6	5	3
190	25	24	22	21	19	18	16	15	13	12	10	9	7	6	4	3

Depth (fsw)	Z	O	N	M	L	K	J	I	H	G	F	E	D	C	B	A
10	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–
15	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–
20	**	**	**	**	**	**	**	**	**	**	**	**	**	**	269	129
25	**	**	**	**	**	**	**	**	**	425	279	201	147	106	73	45
30	+	+	+	+	515	361	281	227	186	152	124	100	79	60	43	28
35	420	338	283	241	207	179	155	133	114	97	82	68	54	42	31	20
40	**	**	**	**	**	**	**	**	**	**	**	**	**	**	240	120
50	+	+	+	+	474	345	272	220	181	149	122	98	78	59	42	27
60	217	194	173	154	137	122	108	95	83	71	61	51	41	32	24	16
70	122	112	102	93	85	77	69	61	54	47	41	34	28	22	17	11
80	86	80	73	68	62	56	51	46	40	36	31	26	22	17	13	9
90	67	62	57	53	49	44	40	36	32	29	25	21	17	14	10	7
100	55	51	47	44	40	37	33	30	27	24	21	18	15	12	9	6
110	46	43	40	37	34	31	29	26	23	20	18	15	13	10	8	5
120	40	37	35	32	30	27	25	23	20	18	16	13	11	9	7	5
130	35	33	31	29	27	24	22	20	18	16	14	12	10	8	6	4
140	32	30	28	26	24	22	20	18	16	14	13	11	9	7	6	4
150	29	27	25	23	22	20	18	17	15	13	12	10	8	7	5	4
160	26	25	23	21	20	18	17	15	14	12	11	9	8	6	5	3
170	24	23	21	20	18	17	15	14	13	11	10	8	7	6	4	3
180	22	21	20	18	17	16	14	13	12	10	9	8	7	5	4	3
190	21	20	18	17	16	15	13	12	11	10	9	7	6	5	4	3
200	20	18	17	16	15	14	13	11	10	9	8	7	6	5	4	3

Depth (fsw)	Z	O	N	M	L	K	J	I	H	G	F	E	D	C	B	A
10	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–
15	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–
20	**	**	**	**	**	**	**	**	**	**	**	**	**	**	420	153
30	**	**	**	**	**	**	626	372	273	211	165	129	99	73	51	31
40	365	303	258	222	192	167	144	125	107	91	77	63	51	39	28	18
50	167	151	137	123	111	99	88	78	68	59	50	42	34	27	19	12
60	113	104	95	87	79	71	64	57	50	44	38	32	26	20	15	10
70	86	79	73	67	61	56	50	45	40	35	30	25	21	16	12	8
80	69	64	60	55	50	46	41	37	33	29	25	21	18	14	10	7
90	58	54	50	46	43	39	35	32	28	25	22	18	15	12	9	6
100	50	47	44	40	37	34	31	28	25	22	19	16	13	11	8	5
110	44	41	38	36	33	30	27	25	22	19	17	14	12	9	7	5
120	39	37	34	32	29	27	25	22	20	18	15	13	11	9	6	4
130	36	33	31	29	27	24	22	20	18	16	14	12	10	8	6	4
140	33	30	28	26	24	22	20	18	17	15	13	11	9	7	5	4
150	30	28	26	24	22	21	19	17	15	14	12	10	8	7	5	3
160	28	26	24	23	21	19	18	16	14	13	11	9	8	6	5	3
170	26	24	23	21	19	18	16	15	13	12	10	9	7	6	4	3

Depth (fsw)	Z	O	N	M	L	K	J	I	H	G	F	E	D	C	B	A
10	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–
15	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–
20	**	**	**	**	**	**	**	**	**	**	**	**	**	**	420	153
25	**	**	**	**	**	**	**	**	**	**	556	296	196	134	88	51
30	**	**	**	**	**	**	626	372	273	211	165	129	99	73	51	31
35	**	**	671	423	325	263	218	181	152	126	104	84	67	51	36	22
40	**	**	**	**	**	**	**	**	**	**	**	**	**	311	166	88
50	**	**	**	**	**	481	339	262	209	168	135	107	84	63	44	27
60	293	252	220	192	168	148	129	112	97	83	70	58	46	36	26	16
70	153	139	126	114	103	92	82	73	64	56	47	40	32	25	18	12
80	107	98	90	82	75	68	61	54	48	42	36	30	25	19	14	9
90	82	76	70	64	59	54	48	43	38	34	29	25	20	16	12	8
100	67	62	58	53	49	44	40	36	32	28	24	21	17	13	10	7
110	57	53	49	45	41	38	34	31	28	24	21	18	15	12	9	6
120	49	46	42	39	36	33	30	27	24	21	19	16	13	10	8	5
130	43	40	38	35	32	29	27	24	22	19	17	14	12	9	7	5
140	39	36	34	31	29	26	24	22	19	17	15	13	11	8	6	4
150	35	33	31	28	26	24	22	20	18	16	14	12	10	8	6	4
160	32	30	28	26	24	22	20	18	16	14	13	11	9	7	5	4
170	30	28	26	24	22	20	19	17	15	13	12	10	8	7	5	3
180	27	26	24	22	21	19	17	16	14	12	11	9	8	6	5	3
190	25	24	22	21	19	18	16	15	13	12	10	9	7	6	4	3

Depth (fsw)	Z	O	N	M	L	K	J	I	H	G	F	E	D	C	B	A
10	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–
15	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–
20	**	**	**	**	**	**	**	**	**	**	**	**	**	**	269	129
25	**	**	**	**	**	**	**	**	**	425	279	201	147	106	73	45
30	+	+	+	+	515	361	281	227	186	152	124	100	79	60	43	28
35	420	338	283	241	207	179	155	133	114	97	82	68	54	42	31	20
40	**	**	**	**	**	**	**	**	**	**	**	**	**	**	240	120
50	+	+	+	+	474	345	272	220	181	149	122	98	78	59	42	27
60	217	194	173	154	137	122	108	95	83	71	61	51	41	32	24	16
70	122	112	102	93	85	77	69	61	54	47	41	34	28	22	17	11
80	86	80	73	68	62	56	51	46	40	36	31	26	22	17	13	9
90	67	62	57	53	49	44	40	36	32	29	25	21	17	14	10	7
100	55	51	47	44	40	37	33	30	27	24	21	18	15	12	9	6
110	46	43	40	37	34	31	29	26	23	20	18	15	13	10	8	5
120	40	37	35	32	30	27	25	23	20	18	16	13	11	9	7	5
130	35	33	31	29	27	24	22	20	18	16	14	12	10	8	6	4
140	32	30	28	26	24	22	20	18	16	14	13	11	9	7	6	4
150	29	27	25	23	22	20	18	17	15	13	12	10	8	7	5	4
160	26	25	23	21	20	18	17	15	14	12	11	9	8	6	5	3
170	24	23	21	20	18	17	15	14	13	11	10	8	7	6	4	3
180	22	21	20	18	17	16	14	13	12	10	9	8	7	5	4	3
190	21	20	18	17	16	15	13	12	11	10	9	7	6	5	4	3
200	20	18	17	16	15	14	13	11	10	9	8	7	6	5	4	3

Depth (fsw)	Z	O	N	M	L	K	J	I	H	G	F	E	D	C	B	A
10	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–
15	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–
20	**	**	**	**	**	**	**	**	**	**	**	**	**	**	420	153
30	**	**	**	**	**	**	626	372	273	211	165	129	99	73	51	31
40	365	303	258	222	192	167	144	125	107	91	77	63	51	39	28	18
50	167	151	137	123	111	99	88	78	68	59	50	42	34	27	19	12
60	113	104	95	87	79	71	64	57	50	44	38	32	26	20	15	10
70	86	79	73	67	61	56	50	45	40	35	30	25	21	16	12	8
80	69	64	60	55	50	46	41	37	33	29	25	21	18	14	10	7
90	58	54	50	46	43	39	35	32	28	25	22	18	15	12	9	6
100	50	47	44	40	37	34	31	28	25	22	19	16	13	11	8	5
110	44	41	38	36	33	30	27	25	22	19	17	14	12	9	7	5
120	39	37	34	32	29	27	25	22	20	18	15	13	11	9	6	4
130	36	33	31	29	27	24	22	20	18	16	14	12	10	8	6	4
140	33	30	28	26	24	22	20	18	17	15	13	11	9	7	5	4
150	30	28	26	24	22	21	19	17	15	14	12	10	8	7	5	3
160	28	26	24	23	21	19	18	16	14	13	11	9	8	6	5	3
170	26	24	23	21	19	18	16	15	13	12	10	9	7	6	4	3

About These Tables#

Table 12-4. Surface-Supplied Helium-Oxygen Decompression Table#

60 FSW#

70 FSW#

80 FSW#

90 FSW#

100 FSW#

110 FSW#

120 FSW#

130 FSW#

140 FSW#

150 FSW#

160 FSW#

170 FSW#

180 FSW#

190 FSW#

200 FSW#

210 FSW#

220 FSW#

230 FSW#

240 FSW#

250 FSW#

260 FSW#

270 FSW#

280 FSW#

290 FSW#

300 FSW#

310 FSW#

320 FSW#

330 FSW#

340 FSW#

350 FSW#

360 FSW#

370 FSW#

380 FSW#

MK 16 MOD 1 Closed-Circuit UBA Tables (1.3 ata ppO2)#

Table 15-8. No Decompression Limits and Repetitive Group Designators for 1.3 ata ppO2 N2O2 Dives#

Table 15-9. Residual Nitrogen Timetable for 1.3 ata ppO2 N2O2 Dives#

Part 1: Surface Interval Credit Table#

Part 2: Residual Nitrogen Times (Minutes)#

Table 15-10. 1.3 ata ppO2 N2O2 Decompression Tables#

60 FSW#

70 FSW#

80 FSW#

90 FSW#

100 FSW#

110 FSW#

120 FSW#

130 FSW#

140 FSW#

150 FSW#

160 FSW#

170 FSW#

180 FSW#

190 FSW#

MK 16 MOD 1 Closed-Circuit UBA Tables — 1.3 ata ppO2 HeO2#

Table 15-11. No Decompression Limits and Repetitive Group Designators for 1.3 ata ppO2 HeO2 Dives#

Table 15-12. Residual Helium Timetable for 1.3 ata ppO2 HeO2 Dives#

Part 1: Surface Interval Credit Table (Helium)#

Part 2: Residual Helium Times (Minutes)#

Table Notes#

Table 15-13. 1.3 ata ppO2 HeO2 Decompression Tables#

30 FSW#

35 FSW#

50 FSW#

60 FSW#

70 FSW#

80 FSW#

90 FSW#

100 FSW#

110 FSW#

120 FSW#

130 FSW#

140 FSW#

150 FSW#

160 FSW#

170 FSW#

180 FSW#

190 FSW#

200 FSW#

About These Tables

Table 12-4. Surface-Supplied Helium-Oxygen Decompression Table

60 FSW

70 FSW

80 FSW

90 FSW

100 FSW

110 FSW

120 FSW

130 FSW

140 FSW

150 FSW

160 FSW

170 FSW

180 FSW

190 FSW

200 FSW

210 FSW

220 FSW

230 FSW

240 FSW

250 FSW

260 FSW

270 FSW

280 FSW

290 FSW

300 FSW

310 FSW

320 FSW

330 FSW

340 FSW

350 FSW

360 FSW

370 FSW

380 FSW

MK 16 MOD 1 Closed-Circuit UBA Tables (1.3 ata ppO2)

Table 15-8. No Decompression Limits and Repetitive Group Designators for 1.3 ata ppO2 N2O2 Dives

Table 15-9. Residual Nitrogen Timetable for 1.3 ata ppO2 N2O2 Dives

Part 1: Surface Interval Credit Table

Part 2: Residual Nitrogen Times (Minutes)

Table 15-10. 1.3 ata ppO2 N2O2 Decompression Tables

60 FSW

70 FSW

80 FSW

90 FSW

100 FSW

110 FSW

120 FSW

130 FSW

140 FSW

150 FSW

160 FSW

170 FSW

180 FSW

190 FSW

MK 16 MOD 1 Closed-Circuit UBA Tables — 1.3 ata ppO2 HeO2

Table 15-11. No Decompression Limits and Repetitive Group Designators for 1.3 ata ppO2 HeO2 Dives

Table 15-12. Residual Helium Timetable for 1.3 ata ppO2 HeO2 Dives

Part 1: Surface Interval Credit Table (Helium)

Part 2: Residual Helium Times (Minutes)

Table Notes

Table 15-13. 1.3 ata ppO2 HeO2 Decompression Tables

30 FSW

35 FSW

50 FSW

60 FSW

70 FSW

80 FSW

90 FSW

100 FSW

110 FSW

120 FSW

130 FSW

140 FSW

150 FSW

160 FSW

170 FSW

180 FSW

190 FSW

200 FSW

Depth (fsw)	Z	O	N	M	L	K	J	I	H	G	F	E	D	C	B	A
10	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–
15	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–
20	**	**	**	**	**	**	**	**	**	**	**	**	**	**	420	153
25	**	**	**	**	**	**	**	**	**	**	556	296	196	134	88	51
30	**	**	**	**	**	**	626	372	273	211	165	129	99	73	51	31
35	**	**	671	423	325	263	218	181	152	126	104	84	67	51	36	22
40	**	**	**	**	**	**	**	**	**	**	**	**	**	311	166	88
50	**	**	**	**	**	481	339	262	209	168	135	107	84	63	44	27
60	293	252	220	192	168	148	129	112	97	83	70	58	46	36	26	16
70	153	139	126	114	103	92	82	73	64	56	47	40	32	25	18	12
80	107	98	90	82	75	68	61	54	48	42	36	30	25	19	14	9
90	82	76	70	64	59	54	48	43	38	34	29	25	20	16	12	8
100	67	62	58	53	49	44	40	36	32	28	24	21	17	13	10	7
110	57	53	49	45	41	38	34	31	28	24	21	18	15	12	9	6
120	49	46	42	39	36	33	30	27	24	21	19	16	13	10	8	5
130	43	40	38	35	32	29	27	24	22	19	17	14	12	9	7	5
140	39	36	34	31	29	26	24	22	19	17	15	13	11	8	6	4
150	35	33	31	28	26	24	22	20	18	16	14	12	10	8	6	4
160	32	30	28	26	24	22	20	18	16	14	13	11	9	7	5	4
170	30	28	26	24	22	20	19	17	15	13	12	10	8	7	5	3
180	27	26	24	22	21	19	17	16	14	12	11	9	8	6	5	3
190	25	24	22	21	19	18	16	15	13	12	10	9	7	6	4	3

Depth (fsw)	Z	O	N	M	L	K	J	I	H	G	F	E	D	C	B	A
10	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–
15	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–
20	**	**	**	**	**	**	**	**	**	**	**	**	**	**	269	129
25	**	**	**	**	**	**	**	**	**	425	279	201	147	106	73	45
30	+	+	+	+	515	361	281	227	186	152	124	100	79	60	43	28
35	420	338	283	241	207	179	155	133	114	97	82	68	54	42	31	20
40	**	**	**	**	**	**	**	**	**	**	**	**	**	**	240	120
50	+	+	+	+	474	345	272	220	181	149	122	98	78	59	42	27
60	217	194	173	154	137	122	108	95	83	71	61	51	41	32	24	16
70	122	112	102	93	85	77	69	61	54	47	41	34	28	22	17	11
80	86	80	73	68	62	56	51	46	40	36	31	26	22	17	13	9
90	67	62	57	53	49	44	40	36	32	29	25	21	17	14	10	7
100	55	51	47	44	40	37	33	30	27	24	21	18	15	12	9	6
110	46	43	40	37	34	31	29	26	23	20	18	15	13	10	8	5
120	40	37	35	32	30	27	25	23	20	18	16	13	11	9	7	5
130	35	33	31	29	27	24	22	20	18	16	14	12	10	8	6	4
140	32	30	28	26	24	22	20	18	16	14	13	11	9	7	6	4
150	29	27	25	23	22	20	18	17	15	13	12	10	8	7	5	4
160	26	25	23	21	20	18	17	15	14	12	11	9	8	6	5	3
170	24	23	21	20	18	17	15	14	13	11	10	8	7	6	4	3
180	22	21	20	18	17	16	14	13	12	10	9	8	7	5	4	3
190	21	20	18	17	16	15	13	12	11	10	9	7	6	5	4	3
200	20	18	17	16	15	14	13	11	10	9	8	7	6	5	4	3

Depth (fsw)	Z	O	N	M	L	K	J	I	H	G	F	E	D	C	B	A
10	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–
15	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–
20	**	**	**	**	**	**	**	**	**	**	**	**	**	**	420	153
30	**	**	**	**	**	**	626	372	273	211	165	129	99	73	51	31
40	365	303	258	222	192	167	144	125	107	91	77	63	51	39	28	18
50	167	151	137	123	111	99	88	78	68	59	50	42	34	27	19	12
60	113	104	95	87	79	71	64	57	50	44	38	32	26	20	15	10
70	86	79	73	67	61	56	50	45	40	35	30	25	21	16	12	8
80	69	64	60	55	50	46	41	37	33	29	25	21	18	14	10	7
90	58	54	50	46	43	39	35	32	28	25	22	18	15	12	9	6
100	50	47	44	40	37	34	31	28	25	22	19	16	13	11	8	5
110	44	41	38	36	33	30	27	25	22	19	17	14	12	9	7	5
120	39	37	34	32	29	27	25	22	20	18	15	13	11	9	6	4
130	36	33	31	29	27	24	22	20	18	16	14	12	10	8	6	4
140	33	30	28	26	24	22	20	18	17	15	13	11	9	7	5	4
150	30	28	26	24	22	21	19	17	15	14	12	10	8	7	5	3
160	28	26	24	23	21	19	18	16	14	13	11	9	8	6	5	3
170	26	24	23	21	19	18	16	15	13	12	10	9	7	6	4	3