Hull Maintenance And Cleaning

Adapted from the Massachusetts Clean Marina Guide

Image of a boat hull


If not properly controlled, hull maintenance activities, including scraping, sanding, pressure washing, and painting, can put toxic pollutants into the marine environment. Where marinas do not provide these services, Do-It-Yourselfers and outside contractors may be performing this work on the marina’s property. In all cases, this section provides you with tools to reduce the potential negative impacts from hull maintenance.

The following laws apply to hull maintenance activities. If you perform hull maintenance services at your facility, please read the summary of these regulatory programs in Chapter 6 of the Massachusetts Clean Marina Guide (see web link above).
  • National Pollutant Discharge Elimination System (NPDES) Multi-Sector
  • General Permit (MSGP) for Industrial Activities
  • Organotin Anti-Fouling Paint Control Act of 1988
  • Massachusetts Air Quality Program
  • Massachusetts Hazardous Waste Regulations
  • Massachusetts Waterways Regulations

Best Management Practices


Because hull paints contain toxic pollutants, they should be used with care. Consider the following BMPs when painting your boat.
  • Designated Maintenance Areas: Restrict mixing of paints, solvents, and reducers, as well as the painting itself, to designated areas that are located on a hard surface and isolated from the weather.
  • Prohibit Spray Painting on the Water: Sprayed paint can be difficult to control. Paint can be inadvertently sprayed into the water and expose marine life to toxic chemicals.
  • Clean Up Paint and Supplies: Treat paint spills like oil spills. Clean up immediately with absorbent materials, paper, and/or rags. Since liquid paints are classified as hazardous material, dispose of paint brushes and paint properly. If your customers are permitted to paint their own boats, require them to clean up after themselves. Provide paint disposal areas for customers to use. Before disposal, all paint cans and worn out brushes and rollers should be allowed to air dry.
  • Appropriate Use and Storage of Hazardous Materials and Waste: Make certain that all painting materials are used strictly according to manufacturers’ instructions. Consult the Material Safety Data Sheets and Massachusetts hazardous waste regulations for proper handling of the products and disposal of unused materials. Keep covers and caps on paints, thinners, and solvents to minimize the release of VOCs. Outside contractors working in your marina must, under terms of your contract with them, comply to the same BMP and cleanup standards as adopted by your business.
  • Spray Booths: A spray booth is a permanent shed or temporary enclosure that can be erected around a boat during painting. Spray booths confine overspray and prevent drifting onto other boats, land, or water. Those booths equipped with air filters reduce impacts on air quality by filtering paint dust and particulates out of the air. In addition, filters help protect workers by drawing harmful fumes and paint overspray away from employees.
  • High Volume, Low Pressure (HVLP) Spray Guns: HVLP spray guns are the most efficient means for applying paint. Promote use of spray guns that are rated at 65 percent efficient paint transfer or greater. These spray guns direct more paint onto the intended surface and, as a result, less paint gets into the air, and less volatile organic compounds (VOCs) are released. In addition, HVLPs save money because less paint is used and clean up costs are reduced. Electrostatic spraying is another option for applying paint so that more paint stays on the boat bottom.
  • Traditional Paint Applications: Use brushes and rollers where possible. Some spray guns can physically agitate the paint during application, which releases more of the chemical compounds into the air. Traditional applications reduce air emissions.
  • Water-Based Paints: Use water-based paints wherever possible. Water-based paints are environmentally-preferable because they use small amounts of VOC solvents. Performance can be just as good as oil-based paints and cleanup is easier because brushes, rollers, and equipment can be cleaned in water, making paint thinners unnecessary.
  • Inform Do-It-Yourselfers: Provide information to your customers who work on their boats at the marina about potential harm to marine waters caused by uncontrolled release of paint products. Visible signs, clauses in customer contracts, fact sheets, and tips in mailings are all good ways to communicate this information.
  • Train Employees: Train your employees to be on the lookout for hull maintenance activities by Do-It-Yourselfers that may be harmful to the coastal environment.

Hull Scraping, Sanding, and Washing

Hull scraping, sanding, and washing releases pollutants that are bound up in hull paint and exposes marine organisms to those pollutants. Employing the following BMPs will minimize the potential for pollutants associated with hull paint to reach coastal waters.
  • Designated Maintenance Areas: Restrict all major vessel repair and maintenance work to designated work areas that are located away from the shoreline. Activities that should be restricted to designated areas include abrasive blasting and pressure washing, hull scraping and sanding, and hull painting. Maintenance work such as painting, scraping, and hull cleaning should be done on land, not at marina slips or moorings. Underwater cleaning of hulls should be prohibited. The area should be provided with containment as outlined below.
  • Containment: Maintenance areas should be designed and equipped to minimize the spread of pollutants by either trapping or filtering runoff. Berms or curbs made of concrete or asphalt can be used to enclose the area and prevent runoff from leaving the maintenance site. To prevent pollutants from seeping into the subsoils, all maintenance areas should be located on top of hard, impermeable surfaces, such as blacktop. Maintenance areas must be covered to prevent rainwater from washing away the remnant pollution left over after work, or alternatively, the work area must drain to an oil/water separator for treatment.
  • Contain Pressure Washwater: The discharge of pressure washwater to surface water or groundwater is illegal without a permit. To properly control pressure washwater, it must be collected and discharged according to permit conditions. Pre-treatment will be required in most cases.
  • Work Indoors: Where practical, conduct vessel maintenance indoors or under temporarily covered areas where the rain cannot cause runoff. Sheet plastic shelters are widely used by many marinas.
  • Work Away from the Water: At a minimum, always move each boat inland to the approved work area before scraping or power washing the hull. Do not allow anyone to do bottom cleaning on the launch ramp area or in the lift well.
  • No In-Water Bottom Cleaning: Removal of seaweed and other marine growth on the bottom of boat hulls by divers must be prohibited. This practice is sometime carried out by owners of sail boats before races in regattas to enhance boat speed. Cleaning of seaweed also removes anti-foulant paint and associated pollutants.
  • Dustless Vacuum Sanders: Dustless sanders use industrial vacuum cleaners to trap sanding dust before it becomes airborne. As the sander removes paint, dust is drawn into holes located in the sanding pad. The dust is sucked into a vacuum container that can be emptied for disposal. Dustless vacuum sanders are one of the best ways to control paint dust before it can become a pollutant. Added advantages include keeping a clean workplace, reducing health risks to workers, and reducing clean-up costs and time. If you choose dustless sanders as a BMP, require all staff, outside vendors, and Do-It-Yourselfers to always use this equipment. Train staff to use equipment and develop a user manual for Do-It-Yourselfers.

Local Example

Parker’s Boatyard in Cataumet, uses vacuum sanders because they are cost effective, cleaner, and more efficient than old sanding methods. Parker’s does not allow people to do their own bottom work at the boatyard for both environmental and economic reasons. Other yards, such as Manchester Marine, e ncourage Do-It-Yourselfers and rent vacuum sanders to them. The rental operation has allowed Manchester Marine to pay off the cost of the sanders and make a small profit. Call Bruce Parker, Parker’s Boatyard at (508) 563-9366 or Rob Hoyle, Manchester Marine at (978) 526-7911 for more information.
  • Tarps and Filter Cloth: Use tarps and/or filter cloth to catch scrapings and other debris produced during maintenance work. Tarps and cloth are inexpensive "low-tech" methods to collect debris before it can be washed into coastal waters. Filter cloths are better than tarps when boat work is expected to last longer than one day, because should it rain, the water passes through the cloth instead of washing the debris off the tarp. Have these items available to rent or sell to customers who do their own boat maintenance.

Local Example

Ryder’s Cove Marina uses filter cloth as a convenient way to contain pollutants produced through boat maintenance. Filter cloths that collect debris are placed under a boat during pressure washing and chipping that collect debris. The pad can be shaken out and chips disposed of off-site. Then the pad can be reused for approximately a week. Call Ryder’s Cove Marina at (508) 945-1064 for more information.
  • Clean Up Designated Areas: Clean up the designated work area after scraping and painting. Leaving areas cluttered and messy will cause spills and allow pollutants to be tracked outside the work area.


U.S. Environmental Protection Agency (EPA) National Pollutant Discharge Elimination System (NPDES) Program. Call (617) 918-1615 or look on-line at for information about the NPDES Multi-Sector General Permit and its requirements.

Massachusetts Environmentally Preferable Products Procurement Program has information on acquiring recycled paints. See their website at .

For more information on pressure washing and related regulatory requirements, contact the Massachusetts Office of Coastal Zone Management at (617) 626-1200.