it was more than likely replaced or removed long ago by a previous owner. every fish finder has its own transducer. when u put the new on u take the old off. or when the old dies some will take it off too. maybe he kept it when he sold it. could also be expoyed to in ur bilge area too. as long as its not on the transom i wouldnt care . it would just be cleaner to cut all the wires and stuff out. most used boats will come with stuff cut out and old sections of it intact. they might cut the wires they see or the ones that bug them or they just didnt like the color of it who knows with some people