From a Bass Boat Central Bass Cat post: Interference with the trolling motors is only improved by isolating the grounds and running a ground from trolling motor head to the foot pedal. We also isolate a ground from cranking battery to the foot pedal. Again this only improves interference and you can contact Lowrance as well as the trolling motor company for more info. It is in no way a situation involving the boats. We have done more work on this topic than any of the electronics and trolling motor companies we know of and we ourselves can not fix it with present systems. The loss of bottom is probably a transducer aging. The loss above 50-60 MPH is air trapping in the hull and blocking the signal. BCB uses a lot of air for performance and that air restricts signal transfer. Keeping the nose trimmed down increases signal till air begins to flow at higher speeds and you loose signal. Transducers primarily read some form of air in the signal, which obviously impairs the signal when air interferes.
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