[oft]

Does anyone know the frequency of the through hull transducer that would have come with a 1976/77 Seafarer 3? I'm hoping to replace this depth sounder with a fish finder (e.g., Furuno LS 4100 {50/200kHz}) without having to replace the transducer (located on the stbd. side of the hull about a foot to the side, and towards the front, of the iron keel). The Seafarer works well enough but seems a little hard to read. Any comments on this idea? I've checked around but cannot seem to find this transducer frequency anywhere. Thank you.