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02/22/2023
Cruising | Sustainability
Antifoul: there's more to consider
To provide you with a little background, antifoul is generally made with copper which acts as a powerful biocide to prevent fouling. The problem with this is that the copper leaches into the water, causing ongoing issues for the water toxicity levels, leading to problems for the marine life. Copper (in excess) is in fact one of the most toxic metals to aquatic organisms and ecosystems! As copper is a biocide or ‘algaecide,’ it causes decreased algal growth when inadvertently discharged into a body of water. Algae are at the base of food chain, so the amount of algae present in an aquatic ecosystem will affect the amount of food available for aquatic animals including zooplankton, insects, shellfish, fish and aquatic mammals. One animal in which the effect of copper has been studied and well documented is salmon. Salmon affected by copper toxicity can be seen suffering from disorientation, stress and difficulties migrating to and from the ocean. The copper also has a major effect on the senses, and as fish rely on their sense of smell to find food, avoid predators and migrate, this is a very problematic effect.
The damage caused by high copper levels is tremendous and takes a long time to recover from. In response, many ports worldwide have banned (for part of the year or permanently) the in-water hull cleaning of recreational boats with copper-based paints, which causes an increased rate of copper leaching into the water. Further, various city councils, ports, environmental groups and the likes are urging boat owners to opt for a copper free antifouling paint moving forward. Washington State has also been working on banning all copper paints with a copper content of more than 0.5% since 2011. This ban is going to be implemented by 2026 (the ban was initially approved for 2018 but there have been some delays). The implementation of these restrictions and bans paints a solid picture of the inherent issues that come with high levels of copper in our waterways.
So are copper-free paints effective in keeping the bottom of your boat clean?
In the past, a big problem with the copper free paints was that they were just not effective enough at keeping fouling at bay and that reputation has stuck. In general, the industry remains of the opinion remains that copper is best and the copper-free alternatives are often overlooked. There are a lot of the up and coming, environmentally-friendly antifouling paints currently in development which have huge potential! Over the next few years we are going to see a lot more products introduced into the market. Along with this there is also already a decent range of alternative paints and coatings available which truly do work to prevent fouling. The paints show to be very effective against algae, slime, barnacles, etc. however commonly require a bit more TLC throughout the year from the boat owner than copper paints. This usually just means taking your boat out for a spin regularly so that unwanted gunk does not get a chance to build up and rather slips off when the boat is travelling at speed (for ablative paints). On a positive note, the alternative antifoul paints generally aren’t affected by a boat being left out of the water for longer periods and simply ‘reactivate’ once in the water. Conventional copper anitfoul coatings can only be out of the water for a few weeks, brand dependent, before they lose their potency and a fresh coat of paint is required.
So on that note, what is the best type of antifoul to use, whether using copper-free alternatives or still resorting to a copper coating?
We’ll begin by discussing the latter and whether there any options which are better if having to opt for a copper antifoul. From the research we have undertaken it would seem that there isn’t a huge difference in self-cleaning, ablative antifoul options versus the hard paint antifoul coatings. Our suggestion if you do go for one of these is to stick with those with a lower copper content. The ablative paints work by gradually releasing copper from the paint over a period of time. This consistent leaching creates imminent issues. The hard paints on the other hand which require scrubbing which releases a large amount of copper in one hit. As they don’t release copper consistently however the difference between the two isn’t all that great. One issue with the hard paints is however the removal process when out of the water, unless the paint is properly disposed of (which it commonly isn’t), the old paint washes straight back into our oceans after the next rainfall… leading to greater issues!
The copper free paints are beginning to look more and more promising. Based off a recent test conducted in the UK to challenge some of the most popular antifoul options, the two biocide free paints came out on top https://www.pbo.co.uk/gear/best-antifouling-paint-head-to-head-test-71025
Whilst the process involved in applying the winning (biocide free) paint was a lot more tedious and specific, the results proved the effort worthwhile. A clean hull only saves you fuel costs and time in your cruising season. Other than the paints discussed in the article, another promising option are ‘slip’ coatings or similar type of paints. These paints work by creating and ultra-slippery surface that the fouling can’t attach to. Anything that does linger slips right off once the boat is moving. As previously mentioned, ample new solutions are also currently in development or going through the testing process and we are closely monitoring the effectiveness of these new products.
Given the awareness of the copper content in waterways is becoming more prevalent around the world, we can only assume that copper based paints will become increasingly less popular and more alternatives will take precedence. Next time you take your boat out for maintenance, maybe ask the shipwright about the alternative options available to coat your hull!
Contact Pantaenius Sail and Motor Yacht Insurance on +61 2 9936 1670, www.pantaenius.com.au for all the right information.
