Check out Super Ship Bottom Paint
My friend Wayne used Super Ship Bottom Ablative paint and his hull looked a heck of a lot better than mine when he pulled her out last fall. I had used a WM ablative paint and wasn't happy with it. This year I'm going to install the SSB paint because it's thinner and goes further, while giving more protection than other bottom paints. I was able to use one gallon of the other paint on my 222 for the two coats, plus a third coat on leading edges and near the surface of the boot top. I still had a little left over in the can, but what good is it if you can't get the protection that you need? Last August I swam under my boat and had to use a scraper to get rid of the barnacles that were slowing my boat down. It's worth paying the extra money for a better paint.