How long does antifouling last?

One of the most common questions boat owners ask is how long antifouling will remain effective. There is no one-size-fits-all answer, as durability depends on a variety of factors, such as the type of antifouling, the conditions of use, and the type of water. In this article, we explain what affects the lifespan of antifouling and how you can maximize its protective effect.

What influences the durability of antifouling?

1. Type of antifouling:

   • Self-polishing antifouling: This wears off continuously, releasing active ingredients. It usually lasts one season per layer.

   • Hard antifouling: It forms a solid layer that slowly releases active ingredients (biocides) and therefore it is not possible to control how well the coating protects.

2. Boat use:

   • Regular use: Frequent trips can wear out self-polishing antifouling faster, while hard antifouling is less affected by movement.

   • Infrequent use: Boats that are mostly idle can develop growth more quickly, even with fresh antifouling.

3. water type:

   • Salt water: Here the growth is more intense, which is why the antifouling is subjected to greater stress.

   • Brackish water: An intermediate area with moderate vegetation.

   • Freshwater: Less vegetation means longer protection.

4. Order and care:

   • The lifespan of the antifouling depends on the quality of the application. Good preparation of the substrate, application of at least two coats and use of a suitable primer are crucial.

How do you know when the antifouling needs to be renewed?

• Visible growth: Algae, mussels or other organisms stick to the hull.

• Color changes: When the bottom layer of color becomes visible (in multi-colored coating), it is time for a new coat.

• Loss of power: The boat is slower or fuel consumption increases.

Tips for extending the lifespan

1. Apply multiple coats: Especially with self-polishing antifouling, different coats of paint can help monitor the condition. The rule of thumb is 1-2 coats per season.

2. Regular cleaning: Remove light deposits during the season with a soft sponge or high-pressure cleaner.

3. Taking the boat out of the water: Inspecting the hull when craned or slipped helps to identify damaged areas at an early stage.

4. Repaint before the season: A fresh coat before launching ensures optimal protection.

Conclusion: How often should antifouling be renewed?

Most boat owners renew the antifouling once a year, often before the start of the season in spring. This is particularly recommended for hard antifouling as you cannot test whether the antifouling is still effective. With self-polishing antifouling you can apply as many layers as you like and only repaint when some of them have worn off. Partial repairs are also possible.