The chum in the paint is very clever. I hope that I remember when the season starts. But to answer the question- it's Micron because it won't build up. Years ago I took the paint off a 27' sail boat. Very bad, very dirty, hard job. On my present boat, a power boat, I use Micron. It goes over any paint that you have on now. On the first application, we put on a green coat and then two black coats. When you see the green, you need to do it again. I think that because you never have to sand or scrap it, it's CHEAPER than the other paint @120 quid a gallon. The boat takes a little more than a gallon. And go the black color. That's my 2 cents.