What is the purpose of a decompression plan and how is it used on site?

• A. To ensure the diver's decompression obligation is met; used to plan stops and gas usage, and adjusts if necessary.
• B. To schedule break times for divers.
• C. To record weather conditions during the dive.
• D. To determine the maximum depth of the dive.

Answer: (A)

A decompression plan is a structured map of the ascent that ensures divers spend the right amount of time at the correct depths to off-gas safely and to manage gas usage. It combines the dive profile (depths and times), the required decompression stops and their durations, the gas strategy for each stage, and contingency steps if the dive deviates from plan.

On site, it serves as the live reference for the team. The supervisor and divers monitor depth and time, follow the prescribed stop sequence and durations, switch breathing gas as planned, and track remaining gas. If conditions change—exertion, currents, delays—the plan is adjusted to maintain safety, such as extending stops, modifying the stop pattern, or reallocating gas, all with the goal of keeping decompression obligations met.

This approach is distinct from tasks like simply scheduling breaks, recording weather conditions, or deciding the maximum depth. Those activities may be part of broader planning, but they do not define the purpose and use of the decompression plan itself.