Hull maintenance

Regular hull maintenance is essential for keeping your boat afloat. Licensing supervisor Debbi Figueiredo explains more about what you need to do and what to look out for.

Whether your boat is made out of steel, wood or plastic there will be times when it will need to come out of the water for essential maintenance.

Steel boats are usually removed from the water for 'blacking' every two to three years, and marine insurance companies request that hull condition surveys happen when a they reach a milestone birthday.

Hull condition survey

A hull condition survey keeps boats properly and comprehensively insured.

Having previously had electrical problems in the hull when first purchased, this also added reassurance that these issues had not returned for us. Steel-hulled boats can turn into a fizzing electrical battery which corrodes the steel if there are stray electrical currents around. This is why boats have anodes fitted, as these fizz away instead of the hull's steel.

Dry-docking

You often have to book a long time in advance, especially if you want a summer month or you moor in an area with a lot of boats.

We booked a week in dry dock at our local boatyard last year along with a surveyor. It's amazing how much water weed and wildlife, like mussels, you find stuck to the hull and it takes some effort to get it off.

Good preparation is the key

After pressure washing, any loose paint and stubborn bits of marine growth need to be removed with a wire brush, either manually or with mechanical help. Finally, any areas of rust need treatment with a rust converter/anti-corrosion protection product before painting can begin.

Removing loose paint from the hull with an angle grinder

Protecting the hull

The final stage of docking is the painting of the hull. In the distant past tar was used to paint boat hulls. More recently bitumen-based paints or Two Pack Epoxy Paint systems are used for steel hulls. GRP or plastic boats use hull treatments that prevent osmosis.

We used a new bitumen water-based paint instead of a traditional bitumen paint. We always try and get at least five coats on below the waterline and at least two above the water line. The new paint allowed us to do eight coats below the water line and four above over the course of four days, before we had to stop painting and allow drying time.

Floating the boat

Once all the tasks have been ticked off, it's time to flood the dock again and make a move.

Last Edited: 22 January 2025