You can make sure your boat is in proper working order. You can outfit your boat with the required safety equipment and know how to use it.You can get a vessel safety check.
You can take a boating safety class. You can be aware of the local navigational hazards. You can check a weather forecast and decide to boat or not. You can leave things that increase your risk – like alcohol – at home.
You probably can't service an engine in the middle of a lake, and you can't put on a life jacket unless you brought one with you.