Pre-Purchase Inspection Guide for Used Marine Equipment

Used marine equipment is bought on evidence. This guide sets out what to inspect, what to request in writing, and how condition terminology should be read. Start with identity Confirm that the nameplate matches the description offered: maker, model, type designation, serial number and rating. Photograph the nameplate. Where the nameplate is missing, treat the identification as unconfirmed until casting marks, drawings or removal records support it. Establish history Ask where the unit came from, what it was fitted to, how long it ran, why it was removed, and how it has been stored since. Removal for vessel recycling, upgrade or damage are very different starting points. A unit stored outdoors and uncovered carries different risk from one stored under cover and preserved. External condition Look for cracks, weld repairs, corrosion at flanges and feet, distorted mounting faces, damaged shafts and threads, missing fasteners, and evidence of overheating or oil leakage. Check that shafts turn freely by hand where it is safe to do so, and note any roughness or catching. Internal condition where access allows For engines and gearboxes, opening reports, bore measurements, bearing inspection and oil analysis are the meaningful evidence. For pumps and compressors, clearances, seal condition and wear at the impeller or rotor matter. Where the seller cannot open the unit, record that no internal inspection was possible rather than assuming the internals are sound. Electrical checks For motors, alternators and switchgear, request insulation resistance readings, winding resistance, and confirmation of voltage, frequency and enclosure rating. Check terminal boxes, cable glands and bearing condition. Completeness Confirm which ancillaries are included: control panels, coolers, pumps, filters, couplings, mounting brackets, sensors, wiring harnesses and manuals. Missing ancillaries are a common hidden cost. Documentation to request Nameplate photographs, general photographs from several angles, dimensional or removal drawings, running-hour records, service history, test or opening reports, and removal or storage notes. Ask which documents exist before agreeing a price; documents that do not exist cannot be produced later. How to read condition wording Used means previously operated, with condition stated as reported. Refurbished is used only where restoration work is confirmed, with the scope of that work described. Tested, certified and class-approved are used only when documentation supports them. Where information is unknown, the correct statement is that it is unknown. Arranging inspection Where the location and seller permit, physical or third-party inspection before commitment is the strongest safeguard. Note that inspection access, timing and cost are agreed case by case.