To replace a boat registration, fill out your state's application for a duplicate registration. Turn in the registration, along with a lost registration replacement fee, at a Department of Motor Vehicles office. In some states, you can file the application over the phone, through the mail or online. If the DMV does not process boat registrations in your state, check with the state's recreation or fish and game departments.
Until you replace your registration or gain proof of registration, do not operate your boat. In some states, you may be able to obtain a temporary registration as proof that your boat is legally registered; this can help you to avoid fines from law enforcement. If you find your old registration, destroy it and use the new one. When you receive your new registration, print a copy for your files.
DMV.org offers a database with state-specific information about how to apply for a boat registration. The database details whether a state's DMV manages registration applications, or whether that is the purview of another agency. Downloadable application forms from each state are available on the site, which also details fees.
Registration processes may vary greatly depending on the state. In Florida, for example, the Department of Highway Safety and Motor Vehicles oversees boat registrations, which are required for any boat that uses the public waterways. Florida's registration exemptions include government-owned boats, lifeboats and temporary nonresident boats. Florida requires that boat owners show proof that they have paid sales tax on a boat before they can register it. Duplicate registration forms are available at county tax collector offices, which also accept completed forms and replacement fees.