We have a 1992 32 GB, had a second depth unit installed with a inside-the-hull transducer, and it works great. I am not sure of the model, the sounder head is a Furuno and I think that it's an Airmar transducer. Looks like the P79 from the Airmar website. It is mounted just to starboard of the rear of the engine. FWIW we have had a number of boats with speed through the water paddle wheels (including our current boat) and I would have traded any of those units for a single rum drink. Good luck!