Echo transducer antifouling paint is used to protect the transducer of a sonar fish finder or depth sounder (echo sounder). Instructions for the fitting of echo sounders indicate that normal antifoul should not be used on the transducer because solvents damage the transducer, the electrical conductivity of the paint reduces the signal and traditional thick antifoul reduces signal strength. Echo is water-based, contains no copper, produces a thin film and therefore minimises the impact on the transducer.