Which information should be recorded in post-dive documentation?

• A. Date/time, location only.
• B. Depths and bottom time only.
• C. Date/time, location, depths, bottom time, gas used, surface interval, environmental conditions, personnel, and any incidents.
• D. Gas used and surface interval only.

Answer: (C)

Post-dive documentation should be a complete record for safety, accountability, and future planning. Recording the date and time anchors when the dive occurred, and the location shows exactly where the activity happened. Capturing depths and bottom time provides the essential dive profile needed to assess decompression obligations and overall exposure. The gas used is crucial because different mixtures affect nitrogen uptake and risk, so knowing what was consumed informs both current safety and planning for subsequent dives. The surface interval since the last dive is important for assessing residual nitrogen and determining whether another dive can be conducted safely. Environmental conditions such as water temperature, currents, and visibility influence thermal stress, equipment performance, and risk assessment. Personnel present identifies who was involved and who is responsible for supervision and decision-making. Finally, noting any incidents—equipment failures, entanglements, medical events—facilitates after-action review, training, and regulatory reporting.

Options that record only a subset miss critical pieces needed for safe risk management and future planning.