What to Look for During an Underwater Hull Inspection

An underwater inspection is one of the most underrated services in boating. Most owners only think about it when something goes wrong — a pre-purchase survey, an insurance claim, or a sale. But routine inspections catch the kinds of slow-developing problems that are much cheaper to fix early than late.

A thorough inspection covers the full hull exterior, every appendage, and every component below the waterline. Here is what we document on a standard inspection:

Hull condition: We look for blisters, cracks, impact damage, and any unusual wear patterns. On fiberglass boats, we are particularly interested in signs of osmotic blistering. On aluminum and steel hulls, we are looking for pitting and galvanic corrosion.

Bottom paint: We assess coverage, adhesion, and overall condition. We note areas of premature wear, exposed primer, and any unusual growth patterns that might indicate a coating failure.

Running gear: Shaft, strut, cutless bearings, propeller, and rudder are all examined for corrosion, damage, and alignment. Propellers get a close look for dings, pitting, and cavitation damage.

Thru-hulls and valves: Every below-waterline penetration is documented. We check the condition of seacocks, look for signs of corrosion around the hull-fitting interface, and verify that everything is intact.

Cathodic protection: Every zinc is identified, measured, and documented. We note percent wear, attachment condition, and whether the protection system is functioning as designed.

Photo and video documentation: We capture HD stills and video of every component, so you have a durable record of your vessel's condition at a specific point in time.

The final deliverable is a written report summarizing all findings, with photographs keyed to specific observations, and our recommendations for any follow-up action. For pre-purchase customers, this report becomes part of your due diligence. For owners, it becomes part of your boat's maintenance history.