How many hours should a crew wait before reporting to duty after scuba diving?

The recommended waiting period before a crew member reports for duty after scuba diving is 24 hours. This guideline is established to minimize the risk of decompression sickness, which can occur due to the formation of nitrogen bubbles in the bloodstream if a diver ascends too quickly or does not allow sufficient time for their body to off-gas the nitrogen absorbed during diving.

By adhering to the 24-hour rule, crew members provide their bodies enough time to eliminate excess nitrogen safely, ensuring that they are in optimal health and capable of performing their duties effectively. This practice is crucial in aviation and other high-altitude professions where the changes in pressure can exacerbate the risks associated with remaining nitrogen in the body post-diving.

The other waiting periods suggested, such as 12, 36, or 48 hours, do not align with the established guidelines and may either be too short or unnecessarily long, impacting operational efficiency without added safety benefits. Thus, 24 hours is seen as the standard and safest recommendation.