Advice on antifouling and how to reduce its environmental impact.

Environmental good practice and antifouling need not be the opposite ends of the spectrum. But do you know how to choose the right antifouling, apply the right quantities, and remove and dispose of the old coatings?

Biocidal antifouling paints are hazardous mixtures that function by preventing the build-up of marine organisms on the hulls of commercial ships and pleasure craft of all sizes. Antifouling paints work largely by releasing biocides into the water, thus preventing organisms from attaching themselves to the bottom of boats.  

Whilst antifouling does a great job of keeping our hulls clean, and even has some environmental benefits such as improving fuel efficiency and preventing the spread of invasive non-native species, it is toxic to aquatic life. Since the banning of TBT in 1987, most antifouls are now copper or zinc based. Some of the compounds found in these antifouls can accumulate in marine organisms, and can find their way into marine wildlife further up the food chain.

The majority of copper in antifouling enters the marine environment through leaching. However concentrated amounts do enter the marine environment during the removal of antifouling paint, which occurs mostly by water blasting or mechanical scraping, and can form concentrated deposits in the sediments around marinas and in river beds. 

Sustainable Boating

You can gain practical advice and learn more about antifouling your boat on The Green Blue website.

Boat owners can play a vital role in preventing concentrated scrapings from entering the water by choosing a marine facility that uses a washdown system that captures run off, and by following the best practice advice available from The Green Blue. A growing number of marinas, clubs and boatyards have installed washdown facilities which collect residues from your boat instead of letting it run back into the water. Some also recycle the wastewater for re-use, preventing pollution and saving water costs.

Some best practice advice includes:

  • Avoid antifoul scrapings entering the water by collecting in a tarpaulin; 
  • Use a dustless vacuum sander to protect your health as the dust from sanding paint and antifouling coatings is toxic; 
  • If you wash your hull off on a slipway, place a length of rope across the slope to catch larger paint particles that can be swept up and put in the hazardous waste bin; 
  • If you use scrubbing piles, only scrub off the fouling and not the underlying paint – be careful not to let old or new paint enter the water; 
  • Select a marina, club or boatyard which has a washdown facility which collects residues and wash down; 
  • Take advice from your chandlery on the correct type of antifoul for your location and use and preferably with the lowest levels of biocides and copper suitable for your needs; 
  • Use water-based paints where possible, or low VOC (Volatile Organic Compounds);   
  • Look into using less damaging bottom paints, such as vinyl, silicone, Teflon or ultrasonic technologies; 
  • Apply the right amount of antifouling required and do not spill it – when applying use a sheet to collect drips; and 
  • Dispose of used brushes, rollers and trays and empty cans of antifoul as hazardous waste.
  • Antifouling products are regulated by the Health and Safety Executive (HSE) and it is the duty of the user to comply with the conditions of use printed on the product’s label. 

    DIY Safe Antifouling Initiative
    The findings of a survey of just under 2,500 boat owners confirmed that over 90% of boat owners are well aware of the hazards involved in the application of antifouling paints, and use the appropriate personal protective equipment accordingly.

    At the start of 2017, the British Coatings Federation teamed up with the RYA and British Marine to launch the DIY Safe Antifouling Initiative 2017. The DIY Safe Antifouling Initiative includes a range of freely-available resources for reference and display, including a poster, trifold, and a guidance document. To find out more, or to download any of these tools, visit