Warm up with a 10-minute tread without using your hands (as much as possible). No grabbing the edge of the pool, but when you start to sink, use your arms to keep you on the surface. But once you have ...

Over a decade ago, the U.S. Coast Guard rescued three men in the Gulf of Mexico who had been fishing for grouper when their boat capsized. In order to survive, they had to tread water for 18 hours.