Under U.S. law all waterborne craft must be registered, and this comes under the remit of the Coast Guard portal. It is basically a matter of filling out the correct forms. If you are a first time owner with a new boat it is a fairly simple affair because just about all the details requested are on the documentation you receive when you buy the vessel. What you need to add are personal details that are a matter of public record. Details that are basic to most applications when obtaining an official license or any other type of documentation.