5 Signs Your Boat’s Antifouling Has Failed
Not sure if your antifouling has failed? These five signs mean it’s time for a hull inspection before performance takes the hit.
Antifouling doesn’t fail overnight. It wears down gradually, and by the time it’s obvious, you’re already losing performance. Here are five antifouling failure signs worth watching for.
1. Sluggish Handling or Higher Fuel Use
This is usually the first sign, and the easiest to miss. A fouled hull creates drag. If your boat feels slower to respond or you’re burning more fuel for the same trips, it’s worth a look below the waterline.
2. Visible Growth Below the Waterline
The clearest sign of all. Algae, weed, or slime building up on the hull means the antifouling has stopped doing its job in that area, even if the rest of the hull still looks fine.
3. Slime or Discolouration
Before hard growth sets in, you’ll often see a slimy film or a change in the paint’s colour. This is early-stage fouling, and it’s the easiest point to catch and treat before it gets worse.
4. Barnacles or Hard Growth
Once barnacles attach, the antifouling has clearly failed in that spot. Hard growth is tougher to remove and does more damage to performance than slime or algae alone.
5. Paint Flaking or Wearing Thin
Sometimes the sign isn’t growth at all — it’s the paint itself. Flaking, chalky patches, or areas worn down to bare gelcoat mean the antifouling barrier is gone, growth or not.
What to Do Next
If any of these sound familiar, don’t wait for it to get worse. We inspect hulls and reapply antifouling for boats across Malta, and can tell you honestly whether a full reapplication is needed or a smaller fix will do.
Get in touch to book an inspection.
