There is a paint especially made for transducers.  I have used it at every bottom cleaning.  Amazon sells it for $19.  Description follows: Reid Gantt Atlantic 30 twin diesel trawler and NauticStar deck boat "Barnacles and marine growth on a transducer is one of the major causes of poor depth sounder performance. MDR's Anti-Fouling Transducer Paint is formulated especially to resist barnacles and marine growth in fresh or salt water, thereby improving depth sounder performance. Transducer Paint is a water-based cuprous oxide, easy to use anti-fouling paint. The brush in the cap makes application easy on both transom and thru hull plastic or bronze transducers. No solvents to worry about. The water based formula will not attack the transducer face like some solvent based bottom paints. Easy clean-up too! 2 oz." On Monday, October 19, 2020 TW Collins via Trawlers-and-Trawlering <twc741@gmail.com> wrote: For decades I have put one coat of bottom paint on my transducers at each haulout  Theory is that one coat of paint will cause less interference than fouling growth. Recent maximum depth readings were on the order of 1450 feet. Tom Collins - Misty Sea Sent from my iPhone. Spelling errors are its fault. _______________________________________________ http://lists.trawlering.com/mailman/listinfo/trawlers_lists.trawlering.com To unsubscribe or modify your subscription options (get password, change email address, etc) go to: http://lists.trawlering.com/mailman/listinfo/trawlers_lists.trawlering.com Trawlers & Trawlering and T&T are trademarks of Water World Productions. Unauthorized use is prohibited.