One thing I learned in naval aviator swim qual was how easy it is to float for a very long time, given the right technique. (Called a dead man’s float. Link: https://www.sportsrec.com/prone-float-8623477.html )

We naturally try to swim with our heavy head out of the water, but with full lungs most people will easily float for almost an unlimited amount of time, only popping your head up for a breath. Somehow, the more nervous you are, the more you struggle to keep your head out of the water. Learning that I could float like this for hours if needed keeps me calm in the water, I recommend you all try it, and keep it in mind to fall back on if you ever start to panic in the water.