What is the best advice to give someone who capsizes in a boat?

Staying with the boat is the best advice for someone who capsizes because a capsized boat can provide buoyancy and is more visible to rescuers than a person in the water. The boat is often a more stable platform and can offer protection from the elements while waiting for help. Additionally, if the boat is relatively unsinkable, it can serve as a point of reference for search and rescue teams.

Swimming to shore immediately might seem like a viable option, but currents, waves, and fatigue can make this dangerous and difficult, especially if the distance to shore is significant. Instead, remaining with the boat increases the chance of survival by allowing for easier identification by rescuers.

Waiting for help on the water without a plan may not be effective since the individual could drift away from rescuers' sight. While signaling for help using a whistle is a good idea and can aid in rescue, it does not provide the benefits of staying with the boat, which increases visibility and maintains a source of flotation.