CRITICAL WARNING: These tables are transcribed from the official U.S. Navy Diving Manual Revision 7 (SS521-AG-PRO-010, 01 December 2016). They must be verified against the original NAVSEA publication before operational use. Transcription errors, however unlikely, could be fatal. Always cross-reference with the official publication.

This section provides the complete U.S. Navy Diving Manual Revision 7 decompression tables for operational reference. These tables are the authoritative standard for U.S. Navy diving operations and are widely used in commercial diving operations worldwide.

Why This Exists

The U.S. Navy dive tables are the foundation of decompression planning for air and mixed-gas diving operations. They provide:

  • No-decompression limits — Maximum bottom times at various depths without required decompression stops
  • Decompression schedules — Required stops, times, and gas switches for decompression dives
  • Repetitive dive procedures — Surface interval credits and residual nitrogen/helium times
  • Altitude considerations — Procedures for diving at altitude or ascending to altitude after diving
  • Mixed gas procedures — Helium-oxygen (HeO2) decompression tables for deeper operations

Operational reality: These tables are used by dive supervisors, commercial divers, and operational personnel worldwide. They must be used correctly and verified against the original publication.

Who This Is For

  • Dive supervisors planning and overseeing diving operations
  • Commercial divers executing dives requiring decompression
  • Safety officers reviewing dive plans and procedures
  • Training personnel teaching decompression procedures
  • Operational planners developing dive procedures and standards

Critical Safety Requirements

Before using these tables operationally:

  1. Verify against original publication — Cross-reference all values with the official NAVSEA publication (SS521-AG-PRO-010)
  2. Proper training required — Users must be trained in decompression table procedures
  3. Medical clearance — Divers must be medically cleared for diving operations
  4. Equipment verification — All diving equipment must be verified and functional
  5. Supervisor oversight — All decompression dives require qualified supervisor oversight

What can go wrong: Incorrect table use, transcription errors, missing updates, improper application. Each failure mode can result in decompression sickness, injury, or death.

Table Categories

USN Air Dive Tables

Complete air decompression tables including an interactive NDL lookup tool:

  • Table 9-5 — Repetitive Groups Associated with Initial Ascent to Altitude
  • Table 9-6 — Required Surface Interval Before Ascent to Altitude After Diving
  • Table 9-7 — No-Decompression Limits and Repetitive Group Designators (10–190 FSW)
  • Table 9-8 — Residual Nitrogen Time Table for Repetitive Air Dives
  • Table 9-9 — Air Decompression Table (descent 75 FPM, ascent 30 FPM)

The air tables page includes an interactive lookup tool for Tables 9-7 and 9-8 — enter depth and bottom time to instantly determine NDL status, repetitive group, and residual nitrogen time for repetitive dives.

USN Helium-Oxygen Dive Tables

Complete helium-oxygen (HeO2) decompression tables including:

  • Table 12-4 — Surface-Supplied HeO2 Decompression Table (60–380+ FSW)
    • Descent rate: 75 FPM | Ascent rate: 30 FPM
    • Mandatory gas switches: HeO2 bottom mix → 50% O2 at 40 FSW → 100% O2 at 30 and 20 FSW
  • MK 16 MOD 1 UBA tables — Closed-circuit rebreather procedures for various oxygen partial pressures
  • Mixed gas procedures — Gas switching procedures and chamber oxygen requirements

Source Information

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

Operational Use

Before operational use:

  1. Obtain official publication — Secure the official NAVSEA publication
  2. Verify all values — Cross-check all table values against the official publication
  3. Training verification — Ensure all personnel are properly trained
  4. Medical clearance — Verify all divers are medically cleared
  5. Equipment check — Verify all equipment is functional and calibrated
  6. Supervisor approval — Obtain qualified supervisor approval for all dives

Responsibility: The dive supervisor is responsible for ensuring correct table use. Incorrect application can result in serious injury or death.

Frequently Asked Questions

What are the U.S. Navy dive tables used for?

The USN dive tables are the primary reference for decompression planning in air and mixed-gas diving. They determine the maximum no-decompression bottom time at any depth, the repetitive group accumulated after surfacing, the required surface interval before a second dive, the residual nitrogen time to add to a repetitive dive, and the full decompression schedule (stops, times, gas) when decompression is required.

What edition is current?

Revision 7 (SS521-AG-PRO-010, 01 December 2016) is the current edition. Always confirm you are using Revision 7 and obtain the official NAVSEA publication before operational use.

Where is the interactive lookup tool?

The USN Air Dive Tables page includes a JavaScript-powered NDL lookup tool for Tables 9-7 and 9-8. Enter depth and bottom time for instant NDL and repetitive group lookup, and enter your surface interval for repetitive dive RNT calculations.