Hull Inspection

In the spring we are all in a rush to get the boat in the water, and it’s tempting to 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 hull inspection by checking for obvious problems:

  • Through-hull fittings
  • Anodes
  • Cracks in the gel coat and haul
  • Blisters
  • Running gear
  • Prop

Hull Inspection

A complete hull inspection can ensure a trouble-free boating season.

Hull Inspection

Check 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 the through-hull transducer to ensure that they are free of deposits that might reduce its effectiveness.


If anodes are more than halfway worn, replace them.


Check the zinc anodes, and replace them if more than halfway worn. The anodes are your boats first line of defense against electrolysis damage.


Look for cracks or gouges that have penetrated the gel coat and exposed the laminate underneath. Once the gel coat has been breached, the chance of moisture intrusion and subsequent damage is significantly 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 seem 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 the water.

The depth of a crack can only be determined by sanding the gel coat away. Cracks that are only as deep as the gel coat are usually not serious and can be sealed with a reapplication of gel coat or an epoxy sealer. If the gel coat 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. They are an indication of 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 that the drying process is complete before making repairs. Like most critical repairs, you should not attempt them without the benefit of a professional.

Running Gear

Inspect the running gear.

Running Gear

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.

Hull Inspection Raw Water Pickup

Clear raw water pickup of marine growth.

Raw Water Pickups

Ensure raw water pickups are clear of marine growth and debris. Marine growth can restrict or even block flow leading to engine overheating or a non-operational saltwater wash-down.


Check the prop(s) for bent or dinged edges. If you experienced any vibration last season, you might have a prop out of balance. A damaged prop can do undo wear on the running gear and reduce fuel economy. It is best to remove the prop(s) and have it repaired and balanced.  

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

~Deane Hislop

Want to read more by Deane? Click HERE.

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