Solvent-based antifouling paint is currently the most common paint available on the market. Examples include Interlux ACT, Interlux Micron 66, Pettit Unepoxy HRT, Sea Hawk Smart Solution AF, TotalBoat Underdog, and TotalBoat Spartan.
Most people known it as bottom paint that comes in a metal can and smells awful, requiring a respirator for application. Formulas have been refined over many years and it has proven its effectiveness.
Increasingly, there's been an environmental push to reduce and ban solvent-based paints because of the toxicity of their solvents, and the high level of VOCs (volatile organic compounds) they contain. Select states have already eliminated the use of solvent-based paints.
The alternative to solvent-based antifoulants is water-based antifouling paints. There are many misconceptions about water-based antifouling paint, including the notions that water-based antifouling paint will dissolve or run in water, and will not work when applied over solvent-based paints.
It's been proven that both statements are wrong. If applied properly and allowed to dry thoroughly, water-based antifoulants are just as effective as solvent-based paints. Water-based paints will still have a slight odor, but it's minimal compared to solvent-based paints.
Another benefit of water-based paints is that cleanup is as easy as using soap and water.
Commonly, water-based antifouling paints come in plastic containers and can be copper-based or copper-free. Examples include Pettit Neptune HRT, Interlux Aqua-One, TotalBoat JD Select, Sea Hawk Monterey and Pettit Hydrocoat ECO.
Both are effective in preventing marine fouling, but personal preference determines whether you want to use solvent-based or water-based paint.