I am sure that I am not the only one who really does not like anti-fouling bottom paint. By definition, anti-fouling bottom paint is a biocide — it kills life — which is fine and dandy if that life is a barnacle. It is not great as I wonder how much dust is getting past my respirator as I prep the bottom of the boat between seasons. I recently learned about ultrasonic anti-fouling systems. I know that I am a bit late to the party as it has been around commercially for at least five or six years now, but it doesn’t seem to be widely accepted quite yet.
The idea is to mount one or more transducers to the inside of a fiberglass, steel or aluminum hull — penetrations required — which will cause the hull to emit high frequency sound interrupting the the growth of slime on the hull as well as the attachment of barnacles. The manufacturers say that the sound is inaudible to humans and does not harm marine life, including fish and marine mammals.
The system, of course, does require power, however, so solar panels or wind generators may be necessary for boats left at moorings. The power requirements could be a
constraint on cruising sailboats, depending on their energy sources.
The biggest question is — does it work? The answer seems to be yes. Graham Snook in Yachting Monthly in 2011 tried ultrasonic for seven months with good results. Charles Doane writing for Sail magazine in 2012, tried an ultrasonic system over a season. After not repainting the bottom, Doane found that there was some growth, but overall was happy with the outcome when the boat was hauled. More recently, in the October 2016 Cruising World, Wally Moran successfully tested ultrasonics on an unpainted hull. From all reports, ultrasonic anti-fouling is not magic, but seems to get the job done.
While I only recently learned about ultrasonic anti-fouling, that just may reflect my own ignorance. There are a range of firms now selling the systems, including Ultrasonic Antifouling, Ltd, Sonic Shield by CMS, SoniHull by NRG, ShipSonic, Jaycar Electronics, Barnacle Zapper, and BarnacleRid. Prices for a two transducer system suitable for a boat between 10 and 16 meters on the waterline range from around $1,000 to $2,000.
Does anyone have any experience with ultrasonic anti-fouling? And if so, what are your thoughts?