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Water Quality Program

Hull Cleaning and Boat Washing

IT’S A FACT: It is illegal to perform underwater cleaning of hulls with soft, toxic coatings (ablative and sloughing). You can face a fine of up to $10,000. (RCW 90.48.080, WAC 173-201A)

Most boats used in marine waters have hulls coated with soft toxic paints (ablative or sloughing) to keep aquatic organisms from attaching. These coatings contain toxic chemicals that are poisonous to salmon and aquatic life. Toxic chemicals are released when you disturb or clean soft toxic paints.

If your boat hull has soft toxic paint, do NOT clean it in or near the water, or near a stormdrain.

Know your hull’s surface before you clean it. If it has soft toxic paint, take your boat out of water to a facility that collects all discharges and debris. To do this work yourself on land, use a tarp and vacuum sander to collect all debris, and dispose of it properly.

What’s the alternative?

New, hard-coatings and epoxy-based hard paints are now available for boat hulls. They provide a slick surface and they are safe for in-water cleaning. The surfaces discourage organism growth, last longer, and minimize harm to the environment. Best of all, these surfaces can improve your boat’s performance and save fuel costs. Check whether one of these coatings could be right for your boat. For more information about non-toxic boat hull products, go to University of California Coastal Resources and view the non-toxic demo page, and access publications. Watch a video from San Diego.

Washing Your Boat

  • Wash with fresh water and spot clean to prevent dirt build up. Do not allow soaps or detergents to enter into the water. Soaps may add nutrients that promote algae bloom. An increase in algae bloom can lead to a decrease in oxygen available to fish and other aquatic animals and can lead to suffocation.
  • Look for catch basins or other collection systems at posted wash areas at local marinas. Pull the boat out of the water to clean the hull and be sure to capture any sediments and dispose of properly. Soft, ablative toxic paints contain toxic materials such as copper, tin, mercury, chromium and lead that are harmful to marine life. Studies of divers cleaning hulls coated with ablative paints shows that concentrations of dissolved copper in the surrounding water exceeded 20 parts per billion. Copper concentrations were elevated to a distance of 100 meters from the hull and concentrations remained elevated for ½ to 2 hours post cleaning.
  • Do not allow excess cleaning products to enter into the water. The most damaging pollutants are those that persist and tend to increase in concentration as they are transferred through the food chain.
  • Use less harmful cleaning methods, including baking soda, vinegar, lemon juice, borax, and good old-fashioned elbow grease.
  • Look for the words “phosphate-free and “biodegradable” on the cleaning products used onboard. Buy only what you need. The smaller the product size, the smaller the potential spill.

The Department of Ecology has determined that some in-water hull cleaning may cause pollution (violation of water quality standards). Cleaning hulls coated with soft toxic paints (ablative or sloughing) causes the release of toxic concentrations of copper. Ecology has also determined that it is not practical to issue NPDES (National Pollutant Discharge Elimination System) permits to divers who clean hulls commercially. Ecology has produced an advisory for divers and boat owners which contains this information and should be posted at several areas in a marina.

Relevant Laws

Report all spills to 800-OILS-911 and 800-424-8802