The man in the Indiana accident also needed to know something else. He needed to feel a sense of discomfort coming on and realize that it was time to stop himself from losing control. But if he was showing off, or under the influence of alcohol, or terrified, he may not have gotten the signals his body was undoubtedly giving him, if only he'd been able to pay attention. One signal was that he had some buoyancy: for 4 minutes, he was not at the bottom. Another was that air was nearby: he was close to the surface, going above and below it...

This is a method of treading water used by water polo players that allows a person to get much more of their body out of the water than any other method. It helps to position your hips slightly behind your shoulders. When you first learn this it can be tiring, but after doing it for a couple of days you get used to it and it becomes highly effective. If you are just learning it do not try to stay in very deep water for too long!