Your life jacket should be snug — really snug. “When you wear a properly fitted vest, it should be hard to breathe when you’re in the store,” says Jeremy Thornell, manager at the Salt Lake City wake shop Marine Products. In fact, think of your life jacket as a second skin. You don’t want any air between you and the jacket, because that air can cause bruised rips when you take a fall. Also, consider that most jackets have a tendency to stretch when wet. When you take a plunge, you don’t want your jacket 3 inches off your shoulder and halfway up your face. Bottom line: If you get an extra large when, in fact, you’re a large, your life jacket isn’t going to be safe or comfortable.