In commercial diving and subsea operations, multiple parties are involved — diving contractors, vessel operators, clients, equipment manufacturers, and regulatory bodies. Ambiguous responsibility is a leading contributor to incidents and to inadequate responses when things go wrong. Clear responsibility allocation is both a safety requirement and a legal necessity.

Why This Exists

When responsibility is unclear, decisions go unmade, safety checks are assumed to be someone else’s job, and post-incident accountability is contested. Defining responsibility boundaries explicitly — in contracts, in pre-dive briefings, and in the operational management system — reduces these risks.

Who This Is For

  • Diving supervisors managing multi-party operations
  • Operations managers building contracts and management systems
  • Legal teams advising on liability allocation
  • Clients and contractors entering into diving services agreements

Key Roles and Their Responsibilities

Diving Supervisor

The diving supervisor has operational authority over all in-water operations. Under UK regulations (Diving at Work Regulations 1997) and equivalent international frameworks:

  • Sole authority over the decision to dive, continue, or abort
  • Cannot be overridden by client, vessel master, or commercial pressure on safety grounds
  • Accountable for ensuring diving is conducted in accordance with the approved dive plan
  • Empowered to call for additional resources, refuse unsafe work, and document deviations

Critical principle: The diving supervisor’s safety authority must be explicitly protected in the contract and cannot be contractually limited.

Diving Contractor / Employer

The diving contractor employs divers and supervisors and is responsible for:

  • Providing competent personnel (appropriately trained and certificated)
  • Providing fit-for-purpose equipment (inspected, maintained, calibrated)
  • Developing the dive management system and procedures
  • Ensuring compliance with applicable regulations
  • Insuring the operation

Vessel Master

The vessel master is responsible for:

  • Vessel safety and seaworthiness
  • Safe positioning and station-keeping during diving
  • Crew safety and emergency response at the vessel level
  • Decisions about vessel movement

Interface issue: The vessel master may need to move the vessel for safety reasons (weather, collision risk) while divers are in the water. Protocols for emergency vessel movement with divers deployed must be agreed and briefed before diving.

Client / Principal

The client commissions the diving operation and is responsible for:

  • Providing accurate information about the work site (existing infrastructure, hazards, access)
  • Defining the work scope clearly
  • Not pressuring the diving contractor to proceed unsafely
  • Ensuring their own personnel do not create hazards for the diving operation

Limitation: Clients cannot direct diving operations. The diving contractor retains operational control.

Equipment Manufacturer / Supplier

Manufacturers are responsible for:

  • Equipment performing to specification under stated operating conditions
  • Providing adequate documentation and training materials
  • Communicating known defects or limitations promptly
  • Supporting incident investigation when equipment failure may be involved

Responsibility Allocation in Contracts

What Must Be in the Contract

Diving services contracts must specify:

  • Which party provides each category of equipment
  • Which party is responsible for equipment inspection and maintenance
  • The diving contractor’s exclusive operational authority
  • Insurance requirements for each party
  • Incident reporting and investigation obligations
  • What constitutes a safe/unsafe worksite and who makes that determination

Indemnities and Liability Caps

Contracts typically allocate liability through mutual indemnities — each party takes responsibility for loss to its own personnel and property. Liability caps limit exposure for consequential losses.

Warning: Indemnity structures that shift safety liability to the diving contractor for client-caused conditions (inadequate site information, client-created hazards) create perverse incentives. Contracts should allocate liability to the party in control of the risk.

Responsibility in Multi-Contractor Operations

Complex offshore operations may involve multiple contractors operating simultaneously. In these situations:

  • Interface agreements — Formal agreements between contractors defining responsibility at operational interfaces
  • Permit to work — Authority for concurrent operations must be clearly assigned to a single coordinating party
  • Simultaneous operations (SIMOPS) — Formal SIMOPS procedures required when diving and other activities occur concurrently

Autonomous Systems and Responsibility

Autonomous vehicles and AI-assisted systems create novel responsibility questions: when an autonomous system makes a decision that causes harm, who is responsible? See Autonomy Challenges & Legacy Assumptions for discussion of how existing responsibility frameworks fail to address autonomous systems.