When it comes to selecting bottom paint, boat owners have many choices. We recently caught up with a few regional experts on the Chesapeake Bay who shared some important information to help you prepare your boat for splash day and find the bottom paint that's right for you.

Types of Paint

Two types of paint commonly used in our region are ablative and modified epoxy, also called hard paint. Here are the basics.


“Most ablative paints have an antifouling agent that works when the boat is moving through the water,” explains George Dunigan, technical sales representative for Interlux Paint and past president of the Marine Trade Association of Maryland. “The movement of the boat causes the paint and any growth to gradually slip off the hull, exposing fresh antifouling agents.” “Since motion is key to effectiveness with most ablatives, the boat needs to be used about once a week for the antifouling agents to work properly. However, there are some newer, high-end ablatives that offer a controlled release, which is effective even when the boat is sitting. These newer ablatives contain self-polishing copper called copolymers, and some of them will last several years with just a scrubbing or light sanding each spring. Most ablatives, however, need a fresh coat at the start of each season.”

Dunigan continues, “One of the biggest advantages of ablative paint is it can come out of the water without losing its antifouling properties. So it’s good for boats that are hauled for more than a month or two. This is not true with hard paint.”

Hard/Modified Epoxy:

Dunigan continues, “An older technology is hard paint, also called modified epoxy. Unlike ablatives, hard paints work all the time, whether or not the boat is moving. The disadvantage with hard paint is their antifouling agents, which contain copper, lose potency when out of the water for more than about 60 days, because the paint begins to lose copper at a faster rate. Around the Chesapeake, some boats only come out for a couple of months each year, so for them it’s not a concern.” Don Zabransky, vice president of sales and marketing for Pettit Marine Paint further explains, “Hard paints are very durable and don’t wear away, but their biocides, which are the antifouling agents, gradually leach out. So even though the paint is in good shape, a fresh coat will be needed to maintain the antifouling properties. Hard paints are best for boats that stay in the water for two to three years and for boats that spend a lot of time at the dock.” Since they don’t wear away like ablatives, after several years of build-up, hard paints will need to be stripped. Generally, modified epoxies are more economical than ablatives, but cost is complex. And paint isn’t a good place to cut corners. “Cost depends upon the ingredients, including the quality and quantity of copper and pigments, but cost is also impacted by the process, including the chemical research behind it,” says Dunigan.

Selecting the Proper Paint

Erik Norrie, CEO of Sea Hawk Paints says, “Over the years I’ve found that it helps boat owners to think through the application of antifoulings in three parts: pre-application, the application process itself, and post application. Breaking a bottom job into digestible segments helps eliminate confusion, ensure expected results, and quantify value in the process.

“Adjust your mindset to embrace the fact that combating marine fouling is an on-going event, not a one-time deal, and begin with the end in mind. Think about the type of antifouling system and the type of hull maintenance your vessel will require. From there, consider hull type, the type and temperature of water your vessel will run in, the time it will be in the water, and what fouling agents you need to combat. The answers to these questions can lead you to an effective antifouling system and program.”

Dunigan puts it this way, “It’s the old ‘who, what, when, where, and how.’ Who is the owner (and what is their price range)? What kind of boat (wood, fiberglass, fishing, racing)? When is the boat used (daily, weekly, only holiday weekends)? Where is the boat (water temperature and salinity where it’s run, as well as whether it’s kept in-water or on a lift or rack)? How is the boat used (is speed important; is the boat trailered)? For example, if the boat is trailered, you need a paint that can withstand hitting the bunks. Generally, hard paints can take abuse better. And they hold their color better, so they look good on the trailer. If your only goal is speed, there are specialty high-speed paints, which are often used by professional fishing captains and others who want to be the first to the fishing hole.

“When it comes to choosing a bottom paint, there isn’t one kind of paint that’s best for every boat,’ says Zabransky. “In fact, the Chesapeake has some of the most challenging antifouling conditions in the country because of the extremely diverse conditions. Some areas are very brackish, while others have mostly fresh water. The Southern Bay and urban areas such as Dundalk tend to stay warmer, while on the Eastern Shore, there’s runoff from farms that impacts the water. The best thing to do is to pick the paint that suits your specific conditions. It’s a good idea to consult the manager of your boatyard or local marine store and ask which type of paint is best for your particular creek or harbor.” “

Quality boatyards perform bottom-jobs every week,” says Norrie. “Engage a reputable yard and ask what challenges you might face and what costs you should expect. New boats, or ones that are well maintained, pose fewer challenges than less well maintained boats, which frequently exhibit bottom blisters, peeling and cracking, and hull damage. Ask if the yard is trained and certified in the coatings they apply and if the manufacturers of the products they use are available for site inspections to aid in the selection, preparation, and application of the correct coating materials.” Dunigan emphasizes, “Whether you’re seeking a recommendation on the best paint to do-it-yourself or hiring someone to do the job for you, make sure it’s someone you know and trust.”


“Regardless if you are protecting a runabout or a yacht, be sure to get a warranty on the antifouling system you have applied,” says Norrie. “Understand the warranty conditions and keep the necessary records so you are covered in the rare case of a failure. Because many warranties may not apply to do-it-yourself jobs, be fastidious in your prep-work and application techniques.”

Norrie continues, “Maintain the hull with routine cleanings. You can contract a pro to do this or set a schedule on your calendar to remind you to do it yourself. Today’s high tech paints are easy to clean and will last much longer with routine maintenance. Additionally when using a self-polishing antifouling paint, apply the first coat in a different color. When you see that color showing through, it’s time for a repaint.”

Water-Based Paints

The introduction of water-based paints has been a big advancement. “Water-based paints work as well as the old solvent-based paints, but they’re much more user friendly and environmentally friendly,” Zabransky says. “With a water-based paint, we take out the solvent, so they have very little odor and clean up with soap and water. They hold their color and work just as well as the old solvent paint. And for boats that stay on a trailer or rack, they’re tough enough to take hitting the bunks.” Although they may have been expensive when they first hit the market, today’s water-based paints come at several price levels. “Not every boat owner needs to purchase the most expensive paint on the market to get good performance and be environmentally friendly,” says Zabransky. “For example, top of the line water-based paints contain Teflon, which makes them slick. If speed is your goal, this may be the paint for you. But if not, there’s no need to pay more for unnecessary additives.”

Environmental Concerns

Marine paint has become increasingly environmentally friendly, but let’s face it—antifouling agents are made to kill organisms that want to live on your boat’s hull. That’s why they’re called biocides. Nevertheless, leading manufacturers are continually improving their products and now offer choices that are increasingly environmentally friendly. Many are lower in volatile organic compounds (VOCs) or solvent-free. “In the last several years, environmental regulations have changed drastically,” says Steven Uhthoff, owner of Annapolis Gelcoat, who has more than 30 years of experience in the marine industry. “Occasionally when it’s time for a fresh coat, the type of paint on a boat is no longer available due to new regulations, but finding and applying a new paint shouldn’t be a problem, if it’s compatible with the existing one.” When it comes to environmental laws, Dunigan emphasizes, “The boat owner should be aware of the changes, but rely on a trusted expert for specifics. Reputable marina managers will know and adhere to environmental regulations, which are sometimes very complex.”

The Future of Paint

“Manufacturers are always refining biocide and the best delivery method. This is where some of the biggest technical advances are occurring,” says Dunigan. “If we can use less copper, that will keep the price down. As we work on delivery systems and foul and release products, the future is a bio-release paint containing silicone. Silicone causes the hull to be so slick the marine organisms just slide right off, with the added advantages of fuel savings and a faster boat. This type of paint is used on supertankers now, but for the most part, it’s still extremely expensive. However, we’re beginning to see it trickle down, and this is something I expect will eventually reach the recreational boater.”

DIY Safety and Prep

“Twenty years ago, you could walk into a boatyard and see about half the work being done by do-it-yourselfers,” says Uhthoff. “Working on the boat used to be part of it, and everyone learned how. Now the majority of people are more into using the boat than doing the work. I’d say that number is down to about five to 10 percent.” Although they may be a dying breed, for some boaters applying a fresh coat of paint is an annual spring ritual, and no amount of mess or tedium will persuade these guys to hire a pro. To the DIYers, we say pay attention to all the details, beginning with safety. Most of the work will be done lying on your back under a trailer or a boat on jack stands. That can be a dangerous place. Make sure the boat is secure. Wear a mask, goggles, and clothing that protects against heavy metals. An organic carbon respirator is a must. “A paper mask you pick up at a home store is not sufficient,” warns Uhthoff.

“Purchase your protective gear at a marine supply store. Even when rolling, the thinner in the paint comes off into the air along with toxins.” Before you begin, read the paint data sheet with the temperatures, overcoat windows, safety standards, and other application information. Use the proper tools for sanding, spraying, and rolling. Again, shop specifically for marine-grade tools. Cheap tape, for example, can leave adhesive on the boat. “Remember that when it comes to antifouling systems, a penny saved is not necessarily a penny earned,” warns Norrie. “Avoid shortcuts in the hull preparation and coatings application. Antifouling paints work best when they bond mechanically and chemically to the hull. This is achieved by proper hull preparation via sandblasting, sanding, and proper priming and painting.”