My boat stays in the water for nine months of the year, so I built a moveable bracket that protects the transom-mount transducer for my fishfinder from algae growth and high-speed motoring. I bought a length of sail track, and a carriage that rides on it, at a yard sale, but they're available at marine-supply stores. I modified the carriage by grinding off the ring and attached the mounting bracket for my transducer to it with screws. Using stainless-steel screws, I screwed the sail track to the transom vertically, so it travels down below the waterline, and sealed all the screw holes with marine silicone sealant. With the transducer and carriage mounted on the sail track, I can pull the transducer up out of the water when I want to run to the grounds or moor the boat, but it's easy to deploy when it's time to fish. I've used it for two seasons and expect it will increase the life of my transducer.