Quick take: Boat material changes the questions to ask, but not the importance of a thorough inspection. Read the full checklist and compare the linked original resources before making a purchase or a high-stakes decision.
For aluminum hulls
Look for corrosion, galvanic issues, stress cracks, signs of poor repairs and damaged fittings. Painted surfaces can hide defects, so do not rely solely on cosmetics.
For fiberglass hulls
Ask about gelcoat cracks, soft areas, water intrusion, past repairs and transom condition. Surface shine does not establish structural condition.
For every used boat
Review engine service, electrical work, title, trailer condition, ownership records and storage history. Evaluate the whole system, not just hull material.
Know when to get a survey
For an expensive or complex purchase, a qualified marine survey and mechanical inspection can reveal problems that a short walkaround cannot. Write down unresolved questions before negotiating.