Really never had an issue with fouling on the paddle wheel sailing in the tropics. Pulled it at the end of the passages so it didn't live in the water for longer than 25 days at a time. Pulling the transducer and capping the puka is no big deal. Get very little water in the boat transitioning from transducer to plug or vice versa. FWIW, calibrated the knot meter to the Walker Log, which was/is accurate, and it never varied more than a percent or so from the Walker. Really like the knot meter because it tells me how the boat is sailing through the water. Only marginally interested in speed over the bottom but getting optimum speed through the water is a big deal. It's the only way to optimize the sailing speed of a boat.