Choosing Antifouling: How to Pick the Right Paint for Your Boat

Antifouling is the paint that protects a boat's underwater surface from marine growth (weed, mussels, barnacles). The wrong choice costs you both performance and money. So how do you pick the right antifouling for your boat?

Why antifouling matters

Growth on the hull adds weight, raises fuel consumption and eventually damages the surface. A good antifouling keeps the hull clean through the season.

Two main types: hard matrix and self-polishing

• Hard matrix antifouling: leaves a hard film that doesn't erode. Suited to high-speed boats, frequently hauled boats and racers. Because build-up accumulates, occasional sanding is needed.
• Self-polishing antifouling: erodes in a controlled way as the boat moves, constantly exposing a fresh surface. Ideal for cruising and low-to-mid-speed boats; less build-up.

Factors that affect the choice

• Hull material: on aluminium boats some copper-based paints cause corrosion; these need copper-free formulas.
• Use and speed: a fast, lightly used boat, or a cruiser constantly under way?
• Water character: warm, nutrient-rich water means more aggressive growth and stronger protection needed.
• Previous paint: new paint must be compatible with the old type; if not, a tie-coat or stripping may be needed.

What to watch in application

Even the best paint fails with poor application. The surface must be clean, dry and correctly sanded, and the number of coats and the maker's drying times must be respected. Extra coats are recommended at the waterline and on moving surfaces.

How often to renew?

For most boats, once a year at the start of the season is ideal. Heavily used boats in warm water may need more frequent care.

If you're unsure which antifouling suits your boat, we'll assess your hull on site under our boat painting and antifouling service and recommend the best system for your material and use.