A diver feels dizzy and confused shortly after surfacing. What should be the immediate concern?

When a diver feels dizzy and confused shortly after surfacing, the immediate concern should be assessing for a possible arterial gas embolism. This condition can occur when nitrogen bubbles formed during a dive enter the bloodstream and obstruct blood vessels, particularly after rapid ascent. The symptoms of dizziness and confusion can indicate that blood flow to the brain is affected, which is a serious medical emergency requiring prompt attention. Recognizing and addressing this potential complication is crucial for the diver's safety and health.

Other considerations such as equipment leaks, dehydration, and buoyancy control are important aspects of diving safety; however, they do not address the acute neurological symptoms presented. While equipment issues and buoyancy are critical for safe diving practices, they are less urgent than ruling out or treating a serious condition like arterial gas embolism, which directly threatens the diver's immediate well-being.