Hull Inspection

Author: Deane Hislop

Whether you are putting your boat in the boatyard to repaint the bottom this spring or launching it after a winter of dry moorage, a complete hull inspection can ensure a trouble-free boating season. In the spring, we are all in a rush to get the boat in the water, and it’s tempting to just launch the boat or paint the bottom and get back to cruising again. But to do so without a thorough hull inspection can be an invitation for trouble.

Begin your inspection by checking for obvious problems, such as through-hull fittings that have suffered electrolytic or physical damage. Pay close attention to the integrity of seals around the fittings. Cracks or separations in the sealing compound can be an indication of movement or shrinkage. They should be attended to before launching the boat. While you’re there, check the exposed surfaces of through-hull transducers to ensure they are free of deposits that might reduce their effectiveness.

Check the zinc anodes, and replace them if they are more than halfway worn. The anodes are your boat’s first line of defense against galvanic corrosion.

Look for cracks or gouges that have penetrated the gelcoat and exposed the laminate underneath. Once the gelcoat has been breached, the chance of moisture intrusion and subsequent damage is greatly increased, making repairs a necessity before launching.

Some cracks, such as those at or near the chines, may be indications of internal problems caused by flexing of the hull under severe use or by the degradation of some internal structural component, such as a weakened stringer. Cracks that appear in a radial pattern are more likely the result of an impact with an underwater object. In either case, outward signs that may appear to be non-threatening could be warning you of more significant problems. They should be investigated thoroughly to determine their cause before you put the hull to the test in a seaway.

The depth of a crack can only be determined by sanding the gelcoat away. Cracks that are only as deep as the gelcoat are usually not serious and can be sealed with a reapplication of gelcoat or an epoxy sealer. If the gelcoat layer is removed and the crack is still apparent, it may be a sign of more significant damage.

Blisters are another common symptom of moisture intrusion, indicating internal damage in the form of delamination. Unfortunately, only the most obvious blisters will be evident in the spring after a long period of dry storage. A better time to check for them is just after the boat has been hauled out and the bottom cleared of marine growth and debris.

Blister repair is a long and involved process. The delamination must be exposed and kept dry for a period of time to allow the captive moisture to evaporate. You need to test the actual moisture content of the composite with a meter to ensure the drying process is complete before making repairs. Like most critical repairs, you should not attempt them without the benefit of a professional.

Like hull condition and through-hulls, running gear should also be looked over and maintained before launching. Shafts, struts and rudders should be inspected before launching. They need to be straight and secure. Cutlass bearings should be checked for lack of play. Trim tabs need to be tested before launching so that necessary repairs can be made with the boat on the hard.

Check the prop(s) for bent or dinged edges. If you experienced any vibration last season, you may have a prop out of balance.

Once your spring hull inspection and repairs are complete, you’re ready to launch and enjoy a carefree cruising season.