How to check a used or project boat before you bid

Every listing says whether the engine runs, what title comes with the boat, whether a trailer is included and where the boat is. Known problems are listed under Known issues. Anything we're not sure about is marked unknown rather than guessed.

Treat unknown as "needs checking" and budget for it. Donated boats are sold as-is: in the condition they're in, with no repairs before sale.

• Cracks. Fine spider cracks in the gelcoat are usually cosmetic. Long cracks, especially near the transom, keel or where the hull meets the deck, can be structural.
• Blisters below the waterline on fiberglass boats that have been left in the water.
• Old repairs: patches, mismatched paint or filler.
• On aluminum boats: corrosion, loose or missing rivets, dents and weld repairs. Leaking rivets are a common fix; a cracked hull is a bigger one.

Many older fiberglass boats have wood inside the transom and floor. If water gets in, the wood rots, and it's one of the most expensive repairs on a boat. Look for cracks around the engine mounting bolts, stains, a soft or patched floor, or a transom that flexes. If the listing doesn't say, ask.

• Does it run? The listing says runs, doesn't run, no engine, or unknown. "Doesn't run" can mean anything from stale fuel to a full rebuild, so budget for the worst case.
• Outboards: look at the lower unit (the part in the water) for damage or leaks.
• Inboards and sterndrives: in cold states, engines that weren't winterized can crack from freezing. Sterndrive bellows (rubber boots) wear out.
• Hours and service history, where the listing gives them.

A trailer saves you a hauler's bill, but check it before a long tow:

• Tires: cracks in the sidewall mean they're old, whatever the tread looks like.
• Wheel bearings, lights and wiring.
• Rust on the frame, axle and springs.
• Winch, strap, bunks or rollers.
• Paperwork: many states title or register trailers separately from the boat.

• Fuel: old fuel goes stale, and fuel lines and tanks may need replacing.
• Electrical: batteries, wiring, switches, navigation lights.
• Seats, carpet and canvas: cheap one at a time, but they add up.
• Safety gear you'll need before going out: life jackets, fire extinguisher, sound signal, as your state requires.

Every listing has an Ask a question button. Ask about anything that matters to your budget: when the engine last ran, soft spots, what paperwork comes with the boat. We answer with what we know.

If a boat turns out not to match its description, there's a 30-day money-back guarantee. See the Terms of sale for details.

Add up the bid, the $499 document processing & boat transfer fee, transport, registration and the repairs you expect, then decide your highest bid. See what boats have sold for and how bidding works.