Can a self-polishing copolymer antifouling that gradually dissolves in the water be a better option than hard antifouling? We put International Micron 77 to the test

Lots of people seem to think that hard antifouling is the way to go for a fast planing boat because its harder finish won’t wear away too quickly. I don’t buy it, partly because it relies on the boat’s motion through the water to wear away the exhausted top layer of antifouling (so it doesn’t work as well when left in a marina) and partly because over the years, you build up countless thick layers of lumpy, part- worn antifouling.

I prefer to use a true self-polishing copolymer antifouling that gradually dissolves in the water, even when the boat is sat on its berth for weeks at a time. Not only does this ensure there is always a fresh layer of biocide-laden paint to keep the critters at bay, but it reduces the buildup of old paint and leaves a smoother, more fuel-efficient finish.

International Micron 77 is one of an increasingly small number of true copolymer antifoulings that you’re still allowed to apply yourself. The other big advantage for workshy lackeys like myself is that two thick coats should last a couple of seasons, which goes some way to offsetting the premium pricing.

boat having antifouling paint applied
That’s exactly what I applied on my Karnic 2250 around this time last year and when I pulled it out of the water at the end of October, the results spoke for themselves.

The underside of the hull was completely free of weed and barnacles and even around the waterline where it was exposed to maximum sunlight, there was only a thin layer of slime. You only have to look at the full beard of weed growing from the small unpainted section of topsides at the stern of the boat to see how bad it could have been.
Even more gratifyingly, there still seems to be plenty of life left in last year’s application, so this spring I will be free to plant up my vegetable patch with lots of baby radishes rather than grovel around under my boat with rollers and facemasks. Result!
For more information click here.

Overall score:

Value ****
Rating *****

Price: £199 for 5 litres