What to Look for in a Used Boat Survey

A used boat survey is the most important safeguard a buyer has when purchasing a second-hand vessel. A pre-purchase survey, conducted by an accredited marine surveyor, examines the hull, structure, engine, rigging, electrics, and safety equipment for defects that are invisible to a casual viewing. The survey report gives the buyer a factual basis for negotiation, a condition for insurance, and — when the findings are serious — a clear reason to walk away. Buyers browsing used boats on Owning should budget for a survey on any vessel over five years old, and should never waive it on a boat above €50,000.

Hull, deck, and moisture

The surveyor begins with the hull and deck, using a moisture meter and percussion sounding to detect water ingress and core delamination. Elevated moisture readings in a GRP hull may indicate osmosis, which requires peeling, drying, and re-coating — a repair that can cost €3,000 to €8,000 on a 40-foot boat. On cored decks, a soft or delaminated section around cleats or stanchion bases signals that water has entered the core, a structural issue that is costly to remedy. The surveyor also checks keel bolts for corrosion and torque, and inspects the rudder stock and bearings for play. A hull out-of-water survey is essential — underwater defects cannot be assessed while the boat is afloat.

Engine, rigging, and systems

On a sailboat, the standing rigging is inspected for visible corrosion, cracked swage fittings, and terminal movement; wire rigging over ten years old is flagged for replacement regardless of appearance. The engine survey includes an oil analysis, a compression or cylinder leak-down test, and a check of cooling, fuel, and exhaust systems for leaks or corrosion. Seacocks should be operational and bonded; seized or corroded seacocks are a sinking risk and are commonly cited in survey reports. The electrical system is checked for proper fusing, grounding, and ABYC compliance, as faulty wiring is a leading cause of boat fires. Buyers should read the full report carefully and ask the surveyor to clarify any "recommendation" or "deficiency" — these terms carry specific weight in insurance underwriting. The full survey checklist provides a more detailed item-by-item reference.