The products you purchase to clean and maintain your boat can be harmful to aquatic life, water quality and human health. Many boat cleaning and maintenance products contain chemicals that are poisonous, corrosive, flammable and/or chemically reactive. Ingredients in certain products content potent caustics and corrosives. Some products contain phosphorous and nitrogen which can cause excessive algae growth that depletes the oxygen necessary to sustain aquatic life. In addition, some ingredients in certain cleaners are heavy metals which bioaccumulate through the food chain and can damage fish tissues.  Cleaning products are not made to be directly released into our waterways. Instead, many cleaning products are created to go through wastewater treatment facilities, where the majority of contaminants and chemicals are removed before the water goes back into rivers, lakes and the ocean.


Save major boat repairs and cleaning for the boat yard where toxic wastewater is collected for treatment and proper disposal.

Tips for the Topside... fish

  • Use a minimum amount of fresh water to clean your boat after every use. This can help reduce the need for harsh chemicals by preventing the buildup of salt, mildew and grime in the first place. Use more elbow grease.

  • Research your cleaners, be a smart buyer. Buyers should be aware of “green washing” claims and information, now common in the marketplace.  When you purchase boat cleaning products, take time to read the label. A signal word, such as “danger/poison,” “warning,” or “caution” can give you a general indication of the toxicity of a product. If you want more information on a product’s contents, ask your retailer or contact the manufacturer for the Material Safety Data Sheet (MSDS). The MSDS will list any constituents considered to be hazardous substances. Labels on cleaning products can be confusing and words like “biodegradable”, “natural”, “non-toxic”, or “organic” are misleading because there is no regulation of the words’ use. In addition, the product’s active ingredients may contain ingredients with incomplete toxicity testing.  In other cases, the actual ingredients have been withheld stating “proprietary” on the label or Material Safety Data Sheet.

  • Leave big cleaning jobs for the boatyard, where toxic wastewater is collected for treatment and proper disposal.

  • Use canvas boat covers to keep boat clean between trips and reduce the amount of cleaning you need to do.

  • Contain spills and debris using tarps.

  • Properly handle and store materials. Dispose of hazardous waste at your county household hazardous waste collection center..

Spill-proof cleaning and maintenance activities:

  • Conduct maintenance work aboard your boat, not on the docks or over the water.

  • Always mix paints, varnish, epoxy and other products over a tarp or in a drip pan to catch spills and drips. Keep absorbents nearby to wipe up spills.

  • Tightly seal product containers when not in use to reduce spills.

  • Plug scuppers to contain spills.

Minimize emissions from surface preparation:

  • Sand and paint large areas only in designated shoreside boat maintenance areas, using vacuum sanders with dust containment bags and high-density low-volume paint sprayers.

  • If performing work outdoors, do not sand or paint on windy days.

  • Use tarps or visquine (sheet plastic) to catch and control falling debris, and vacuum or sweep frequently to prevent discharge of debris into the water.

  • For small jobs conducted in-water, attach tarps or visquine from boat to dock to catch debris. Reverse boat in the slip to work on the other side.

  • Plug scuppers to contain dust, debris and spills.

On the Bottomside:

Marina Oil Workshops
  • If marine growth on the boat needs to be removed using abrasive cleaning methods that may also remove paint from the boat, haul the boat out of the water for cleaning.

  • Regularly clean the hull to extend the life of the hull paint and to avoid hard fouling growth that requires more abrasive cleaning.

  • Clean with non-abrasive methods, such as with a soft cloth, fleece mitt, soft carpet or a long, bristled soft brush.

  • Avoid aggressive cleaning—with scrapers, abrasives, powered rotary brushes—as it may cause the paint to slough off, releasing copper or biocide unnecessarily.

  • Employ or contract with divers formally trained in environmentally sound hull-cleaning best management practices, such as those by the California Professional Divers Association, which are currently the only standards available in California.

  • Consider using non-biocide bottom paints, which do not release chemicals such as zinc and copper, or low-leach rate copper paints on your boat.

  • Check the “Boater's Guide to Using Hull Paint in California” when selecting a bottom hull paint. This brochure provides an easy-to-read format and key considerations.

  • When divers need to replace zinc anodes, collect them for recycling by a local scrap-metal recycler.