What is the recommended surface observation time for a diver who makes an uncontrolled ascent but is within no-decompression limits?

For a diver who makes an uncontrolled ascent but remains within no-decompression limits, the recommended surface observation time is 1 hour. This is based on safety protocols established to monitor divers after they have experienced a potentially hazardous ascent scenario.

The 1-hour observation period allows for sufficient time to detect any signs of decompression sickness or other diving-related issues that might arise from the ascent, even when no-decompression limits are respected. While the diver may not have violated decompression protocols, uncontrolled ascents are still considered risky as they can lead to physiological stresses on the body, such as nitrogen bubbles forming in the blood and tissues.

By monitoring for at least 1 hour, dive supervisors can ensure that the diver remains stable and can respond promptly if any symptoms of decompression sickness manifest. This precautionary measure enhances the diver's safety and well-being after an uncontrolled ascent. Other options, such as shorter observation times or no observation at all, do not provide adequate safety assurances after such an incident.