Boat and Engine Surveys Explained
A marine survey is a documented inspection of a vessel by a professional surveyor. Buyers use a pre-purchase survey to learn the real condition of a boat before closing, and many insurers and lenders ask for a survey on older or larger boats. The report is written for the person who pays for it, which is one reason buyers are advised to hire a surveyor who is independent of the seller and the broker.
What a Pre-Purchase Survey Covers
- Hull and deck: moisture readings, tapping or sounding for delamination, blisters, cracks, stress marks and previous repairs.
- Structure: transom, stringers, bulkheads and motor mounts, which hide the most expensive problems.
- Systems: electrical panel and wiring, bilge pumps, steering, through-hull fittings, fuel tanks and lines.
- Safety equipment: life jackets, fire extinguishers, flares, navigation lights and sound signals.
- Haul-out and a sea trial in many cases, so the bottom, running gear and the engines under load can be examined.
Where the Engine Fits In
Surveyors look at engines, but they are not always engine specialists. Many buyers pair the hull survey with a separate mechanical or engine survey carried out by a technician trained on that brand. Typical engine checks include a compression or leak-down test, an oil and coolant condition check, a review of hours and service records, and a test run to see whether the engine reaches the rated wide-open-throttle RPM. Oil analysis can add information about internal wear.
Choosing a Surveyor
Two professional bodies commonly referenced in the United States are the Society of Accredited Marine Surveyors (SAMS) and the National Association of Marine Surveyors (NAMS). Membership is not a guarantee, so ask about experience with your type and size of boat, request a sample report, confirm that the surveyor carries professional liability insurance and that the scope of work is agreed in writing.
Using the Report
A survey rarely finds nothing. Findings are normally sorted by urgency: safety items first, then repairs needed soon, then cosmetic or advisory notes. Buyers use the list to negotiate the price, ask the seller to fix items, or walk away. Survey costs are usually quoted per foot of boat length, and they vary by region and boat type, so compare several quotes. A survey describes the boat on the day of inspection and is not a warranty.
After the purchase, a baseline is useful for the routines in the maintenance guide. For the safety-equipment side, see boat inspections.