Guidance on diving operations in support of underwater ship husbandry

Summary

Underwater ship husbandry (UWSH) entails all aspects of maintenance, cleaning, and general upkeep of the hull (including valves, sea chests, intakes, and discharges) and associated appendages (such as propulsion systems) of a ship or other floating structure.

Around the world, many divers have been killed, suffered life changing injuries, or have experienced long term health conditions due to their involvement in unsafe UWSH operations.

These incidents have in the main, arisen from:

• activation of the vessel’s propulsion systems
• activation of the vessel’s machinery (e.g. pumps) causing differential pressure
• differential pressure created when by the failure of, or incorrect removal of bungs (e.g. plugs or stoppers) from vessel discharges or intakes
• differential pressure caused by a failure of the vessel’s hull integrity
• exposure to toxic antifouling materials
• exposure to biological and chemical hazards, and
• inadequate planning, management, and execution of the diving project.

Vessel owners and operators frequently have a need for UWSH to repair, maintain or survey a vessel’s hull and its underwater appendages. UWSH projects normally comprise of one or more of the following.

Contents

• Background
• Glossary of Terms
• Aims
• Application
• Selection of Diving Contractors to Undertake Underwater Ship Husbandry
• Roles and Responsibilities
• Personnel
• Diving Equipment Setup Locations
• Equipment
• Dive Planning and Procedures
• Risk Assessment
• Permit to Work
• Hazards Associated with Underwater Ship Husbandry
• References
• Appendix 1 – Underwater Ship Husbandry Diving Contractor Assurance Checklist
• Appendix 2 – Underwater Ship Husbandry Risk Register
• Appendix 3 – Example of an Underwater Ship Husbandry Work Permit
• Appendix 4 – Example of a Checklist for the Use of Plugs, Blanks and Cofferdams

Version history

January 2024 – Initial publication