A person who buys a boat acquires a body of law nobody explains to them, and a person injured on one discovers rules very different from those governing a car crash. This article explains recreational boating law as it actually operates. It covers when federal admiralty jurisdiction attaches, why the forum choice is the first strategic decision in any case, and how the navigation rules — not traffic intuition — decide fault. It works through the criminal statutes for negligent operation and for failing to render assistance, the short casualty reporting deadlines that produce the document every later proceeding is built on, and the nineteenth-century limitation statute that can cap a defendant's exposure at the post-accident value of the wreck. It closes with registration, documentation, insurance, and the questions every owner gets wrong.