I use bottom treatment. Not paint. When Lake Erie warms up enough, I jump in and scrub the bottom. My treatment doesn't really stop the growth, but A] slows it down and B] easy to wipe off. I'm in the water anyways.
Sad thing for this year and beyond, I have a little less then half a bottle remaining. I think I have the last bottle ever manufactured. It's no longer around anywhere even in Canada where it is/was made. I tracked down the person in charge and he tried to con me into giving him my CC and he'd ship me some treatment. I didn't take the hook!
This stuff was amazing. One coating underneath and you're done for the season. No need to polish it. It did what it stated. The alternative is awful. Two coats of heavy paste. While it works just the same, it is hard to apply forcing me to crawl around under the boat and over the axles. No fun. But the cost of the paint....