Depends what drand, most manufacturers say yes, as long as the bottom is smooth and does not have a lot of layer on it. I believe you will need to sand the non ablative down first and then run a rag with paint thinner over to clean it then paint. If you go to interlux's website, they tell you what their ablative paints will work with out of their paints, and how to prep the bottom to make it work. If yyou have another brand, I'm sure it would work but you may have to call them to see what they would recommend. If you have a lot of bottom paint on the boat already, you really need to blast it off and start over, if it is a coat or two and smooth you are fine. If it is almost smooth, 80grit sand paper will get it smooth enough. I had non ablative on my old boat, after having abaltive on the new one and not having to paint the bottom every season very nice. I've also found the ablative does a better job at keeping my bottom clean.