The info on hypothermia is good, and I believe it.

However, he omits to empahsise the importance of not going overboard.

Most boats have lifelines about 2 feet high. They are trip wires. Best bring them up to 3 feet, but that is difficult to do on most boats.

Useful although flotaton is, good lifelines, grab rails and (when it is rough, a safety harness) are more useful.

Another point, a floatcoat (Mustang or similar) is far better than a lifejacket, becasue it provides a fair bit of hypothermia pretections as well as floatation. Also, it is comfortable, so it gets worn more. I built a safety harness into mine , becasue I have not found a floatcoat / harness combination that is i comfortable and effective.