Alaskan boaters are often a long way from assistance and the water is very cold. An unprepared boater is taking unnecessary risks. Most fatalities are due to hypothermia related drowning, following an unexpected immersion in cold water. Expert swimmers are powerless against the rapid onset of immersion hypothermia. It's the law for kids under 13.
Most boating fatalities are a result of a sudden capsize or fall overboard.
Don't overload your boat, and be ever watchful of the weather. Be prepared to stay in a safe place until the weather improves. Never mix alcohol and boating. Alcohol impairs judgement, your most important tool on the water. It also slows reaction time, speeds the effects of hypothermia, and affects balance and vision.