You cannot use just any type of paint. For example, if the existing paint on the boat is a "hard, non-ablative" paint, you cannot just cover it with an ablative paint, without proper preparation. It sure helps when you know what was put on previously. However, if you put a coat of Primocon on (Interlux product) you can then use almost any anti-fouling paint. My suggestion is you go to YACHTPAINT.COM which is Interlux' website. There is so much information there and your questions will be answered. As a start, click on "BOAT PAINTING GUIDE" on the left side, then on "ANTIFOULING" in the middle of the page. From there you will see FAQs and a paint compatibility chart. It's a start and I hope it helps. Good luck.