Tried them all!
After forty years of painting the bottoms of my boats, I think I have tried most everything. In the early days (fifties and sixties)we (crew)would sand the bottom with 80 grit, then a light first coat of whatever was popular then in bottom paints. Then another sanding with 100 grit. Then one coat of regular bottom paint. At this point you switch from regular sand paper to wet/dry 200 grit paper and do the bottom. More paint and 440 grit wet/dry. Next you put the boat in the water for two weeks, haul again and everyone burnishes with burlap until it shines.One year we tried spray painting (with professionals) but we didn't see any difference and it was more expensive.We also tried white bottom paint because they said it was faster. Probably is becuase you see the growth faster and you have the bottom scrubed more often.That was for racing bottoms. Now I cruise (well, I race but not so intently), and we make sure the bottom is smooth and then put two coats of whatever is popular. Right now I'm using Ultima for the first time. Pure gold by the cost of it. Last year the haul out people did a power wash and did it too strongly and the bottom because very rough because I was using an ablative paint. This year I had the bottom scraped smooth and then two coats of paint put on. Light power washes from now on.For racing you probably have to use a hard paint. But the problem is that after three or four years it has to come off--in my past life, that meant sanding.I would suggest for those with new boats or those starting over to put on a coat of one color (let's say RED) and then put the next two coats on of the color you want (in my case BLUE). That way when you see the red showing through, its time to repaint. Particularly with ablative paints.I've also used Peal-A-Way and it was excellent although expensive. It took all the paint off to the fiberglass and was not messy as well. Just roll up the paper and toss it.This year I hired a company to help paint the bottom. They did the scrapping and prep work and then we all did the painting.By the way, if you have extra paint, put an extra coat around just below the boot line. This is where sun gets in and helps more growth to survie.In the pacific northwest, I paint every year. It's $500 for the haul out and $300 for the paint. I paid a lot for this boat and it seems to me to be not too much money to check the bottom and make sure the boat sails well.And no, I don't sand the bottom anymore with my Hunters. I think paints have improved and the bottom seems to me to be about the same smoothness.Painting is a bit like hitting you head against a brick wall--you'll feel so good when it all over. By the way, this is where skippers/owners ought to practice standing in a cold shower tearing up hundred dollar bills. It will get you in the mood. Hope this helps someone.Have fun!