Why is submerging under the water a good idea if a struggling person grabs you around the neck?

Submerging under the water when a struggling person has latched onto you can be an effective safety strategy because it disrupts their instinctual response to cling to whatever might allow them to stay afloat. When you go underwater, the person may instinctively let go in an attempt to reach the surface for air. Their primary drive is to breathe, and if they realize that holding onto you is preventing them from doing so, they are more likely to release their grip.

This action is based on the understanding of how someone in distress reacts when they feel their life is in jeopardy. When underwater, the immediate need for air takes precedence over other instincts, making it a tactical move that could help both the lifeguard and the struggling individual. This tactic differentiates itself from options that might seem beneficial, such as confusing the person or encouraging them to hold on, which could exacerbate the situation rather than resolve it.