How to Inspect a Vessel Before Buying: The Complete Checklist
From hull condition to engine hours, here's everything you need to check before making an offer on a used vessel.
Why Pre-Purchase Inspections Matter
A vessel is one of the largest capital investments a maritime company will make. Skipping or rushing the inspection process can lead to costly surprises — from hidden structural damage to pending class requirements that could ground the vessel for months.
This guide covers every step of a thorough pre-purchase inspection, whether you're buying a dredger, tug, barge, or offshore vessel.
1. Hull and Structural Integrity
- Underwater hull inspection: Hire a diver or request a drydock survey. Look for corrosion, pitting, weld repairs, and plate thickness measurements.
- Deck and superstructure: Check for cracks, deformation, and drainage issues. Pay attention to welded joints and fatigue-prone areas.
- Ballast tanks: Internal coating condition is critical. Recoating can cost $500K+ on larger vessels.
2. Machinery and Propulsion
- Main engines: Request running hour logs, overhaul history, and oil analysis reports. Compare actual hours to manufacturer service intervals.
- Generators: Check load test results and fuel consumption records.
- Propulsion system: Inspect propeller condition, shaft alignment, and stern tube seals.
- Auxiliary systems: Pumps, compressors, hydraulics, and electrical switchboards.
3. Class and Certificates
- Class status: Verify the vessel is "in class" with no outstanding conditions or recommendations.
- Special survey: Check when the last special survey was completed and when the next is due. A vessel approaching special survey will need significant investment.
- Statutory certificates: Safety equipment, MARPOL compliance, load line, tonnage — all must be current.
4. Documentation Review
- General Arrangement drawings
- Stability booklet
- Class survey reports (last 3 years minimum)
- Drydock reports
- Maintenance and repair logs
- Crew certificates and manning requirements
5. Sea Trial
Always request a sea trial. This is your chance to verify engine performance under load, check for vibrations, test navigation equipment, and assess the vessel's handling characteristics. A seller who refuses a sea trial is a red flag.
Final Tip
Budget 1–3% of the purchase price for the inspection process itself (surveyor fees, drydocking, travel). This investment protects you from far larger costs down the line. On TradeVessels, you can message sellers directly to request documentation and arrange inspections before making an offer.