When TBT was banned as the active ingredient, antifouling became less effective. Copper was hailed as a more environmentally friendly biocide, but just didn't quite seem to work as well. Then along came International Optima, a revolutionary water-based, two-pot paint, at the time probably the most expensive antifouling on the market.
The price put us off at first. But when we saw it in action on friends' boats, we were impressed. Still copper-powered, it really did seem to be in a league of its own in terms of repelling fouling. So, after it had been around for a couple of seasons, we put Optima on the Sigma we then had.
The first surprise was that we actually saved some money, because up until then we'd been putting on a new coat mid-season (I think we have a particularly bad fouling problem where we are based on the East Coast) and now we found we didn't need to.
So Optima became our antifoul of choice.
It is not without its drawbacks, however. The first is that, being water-based, you have to be particularly careful about the weather when you apply it. If it gets rained on before it has cured, it literally washes off the hull. We have seen it happen!
It must be warm enough, too, or the two-pack mix doesn't cure properly, and the result is impaired adhesion and performance. So on occasion we have had to take it back to the shop and swap it for something less sensitive, as launch day deadline approaches and the weather stays cool and damp.
It's not properly white, either. Racers like white antifoul because you can see as soon as there is any growth on it, and do something about it, while diehard cruisers prefer dark colours so that slime doesn't show. While we had the Sigma it was always white. “White” Optima does go white underwater, but above the waterline it turns an unattractive grey-green, so we had to paint the boot-top with white Trilux.
For 2006, we put black Optima on our current boat, boot top and all. Folklore says the dark colours perform better than white because there is more of the active ingredient in them. I don't know whether this is true or not. It could be that they are more effective because they reduce the light level close to the hull. But certainly the black antifoul did an impressive job of keeping the slime at bay until the very end of the season (and the boat stayed in the water until the New Year). It didn't discolour above the waterline, either.
The other drawback of Optima is that it appears to erode a little unevenly, and when the boat came out of the water it was slightly pitted here and there, not enough to affect cruising performance significantly, but enough to dismay a racing perfectionist.
And it's tricky stuff to get off, too. Although it is a “soft” (self-polishing) antifoul, it sets extremely hard once out of the water, and defies the most determined application of wet-and-dry. You either have to smooth it back with a power sander, or scrape it off completely to restore a fair surface.
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If fouling is your main concern, Optima does an excellent job. You have to wait for the right conditions to put it on - and then face some hard work taking it off. But strong performance makes it worth the effort - and the premium price.
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For more information visit www.yachtpaint.com
