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4.2E – Operation and Maintenance – Underwater Boat Hull Cleaning and Maintenance

Management Measure

For boats that are in the water, perform underwater hull cleaning and maintenance operations to minimize, to the maximum extent practicable, the release of paint, invasive species, and anodes.

Consider using a nontoxic or other legal boat hull paint rather than a copper-based antifouling paint.

Management Practices

For Marina Owners and Operators:

  • Provide boaters with educational materials and programs, in addition to the resources they need to management practices that are included in this encyclopedia.
  • Consider starting a program that helps boaters switch from copper-based antifouling paints to nontoxic or other types of legal boat hull paints.
  • Allow only certified professional underwater boat hull cleaning services to perform work at your marina.

For Boaters:

  • Be sure to use only legal bottom paints, and depending on boat use, consider a hard non-ablative paint that might last longer. Consider switching from a copper-based antifouling paint to long-lasting and low-toxicity or nontoxic antifouling paints. New environmentally friendly alternative paints are being developed, so ask around for the latest and best.
  • See Management Measure 4.2I. for the best way to handle used paint.
  • Hire only certified professional underwater boat hull cleaning services to perform work on your boat.


  • Nontoxic Bottom Paint Demonstration Project by the University of California, Davis, Sea Grant Extension Program in San Diego County provides educational resources and conducts field demonstrations of nontoxic boat bottom paints.
  • San Diego Unified Port District, Alternative Hull Paint Project is funded by a USEPA grant and is designed to identify viable alternatives to copper-based hull paint and work collectively to encourage the transition to these paints.

Information Resources

  • California Department of Pesticide Regulation and Surface Water Protection Program contains documents produced by the Department of Pesticide Regulation’s Copper Antifouling Paint Sub-Workgroup to assess the degree and geographical distribution of copper pollution in California aquatic environments. Documents include meeting agendas and notes, a report on copper sources in urban runoff and shoreline activities, copper monitoring studies in California with potential relevance to the evaluation of copper antifouling paint pollution studies, a summary of a workshop on alternative anti-fouling bottom paints, a bibliography of aquatic copper and antifouling paint studies, monitoring programs and marina sampling data.
  • California Professional Divers Association (CPDA) develops the content and instruction format for the NPS/Diving Hull Cleaners BMP Certification Course and continues to conduct research to update the course information and content. More information about the certification program can be found at the California Professional Divers Association Website. See a list of certified divers.
  • University of California Cooperative Extension, Selecting a Hull Paint for Your Boat this fact provides tips on the most environmentally sound practices related to antifouling.
  • University of California Cooperative Extension, Selecting Underwater and Topside Maintenance Services for Your Boat , this fact sheet provides guidance on the selection of a professional maintenance service that will follow environmentally sound procedures.
  • University of California Cooperative Extension, Underwater Hull Cleaner’s Best Management Practices this fact sheet is for professionals and describes ways to lower costs as well as to help the environment with management practices that reduce pollution and extend the life of hull paints.


USEPA. 2001. National Management Measures Guidance to Control Nonpoint Source Pollution from Marinas and Recreational Boating. EPA 841-B-01-005. U.S. Environmental Protection Agency, Washington, DC. Retrieved on March 16, 2008 from http://www.epa.gov/owow/nps/mmsp/index.html