A Hard Solution
Contact-leaching paints are moderately hard bottom paints; they include hard epoxy, modified epoxy, oil, and alkyd paints. The biocide leaches out of the paint when it comes into contact with water. Eventually the biocide is gone, and an insoluble film remains, so after 10 years of repainting, you've got a thick layer cake on your bottom. These paints have a fairly smooth finish, and they can be loaded with biocides--usually cuprous oxide--so you can get long-term coverage (up to two years), even in some tropical waters. The industry leaders in the United States, International Paints (Interlux) and Pettit, have added some great slime-fighting biocides that cut down on the need for bottom scrubbing. A test group at our sister publication, Sailing World, found good results with the Interlux Ultra-Kote, which has Teflon, making it durable and easy to clean. Pettit's Trinidad SR also has a loyal following, particularly among warm-water cruisers. If you're looking for a water-soluble hard paint, Interlux's relatively new Bottomkote Aqua, with low VOCs, allows for easy soap-and-water cleanup.