https://www.dropbox.com/s/2htblj2p8idua ... s.JPG?dl=0I agree, get a Garmin, I put one in about 3 years ago and its one of the best upgrades I have done. I used to have an old school Humminbird fishfinder/sounder that used to lose bottom at planing speeds. The Garmin never does, and has a lot of other neat features.
My old boat did have some kind of a sounder from the factory, but the read out was long since removed from the dash (there was just a hole there, now I have a gas vapor detector in that spot) but the transducer is still glued to the inside of the hull. When I installed the Garmin I used a transom mount transducer and I interfaced the Garmin with the VHF radio, to give one push button emergency call functions (Your radio will transmit your lat&lon coordinates).