If unable to exit the water during an underwater explosion, what position should a diver adopt to minimize injuries?

Floating face up and presenting thicker tissues to the explosion is the recommended position for a diver in the event of an underwater explosion. This posture allows the diver's body to use the natural buoyancy of water to help absorb some of the shock waves created by the explosion.

By lying face up, the diver effectively positions more robust areas of their body towards the source of the blast. Human tissue resistance can help mitigate potential injuries, as denser structures — such as the chest and the head — are more likely to withstand the pressure from the shock wave.

This position also allows for a potential reduction in the risk of internal injuries by providing a more even distribution of force across the body's surface rather than concentrating it in vulnerable areas.

Other positions would not afford the same level of protection. For instance, floating face down could lead to increased risk of injury as the diver's back and more vulnerable areas would take the brunt of any pressure wave. Additionally, floating head down with legs tucked would not provide adequate defense against the blast, and floating face up with feet towards the explosion may not effectively leverage the body's structure to minimize impact.