I have a B&G Hydra 330 system that works fine, but it's getting old and I'd like to have back-up depth capability. The simplest solution would probably be to remove the B&G speedo thru-hull, which I don't use, and install an Airmar transducer in its place. The B&G is 170 kHz, the Airmar 235 kHz. I'm curious if they will interfere with each other. Obviously I could leave the Airmar unplugged unless/until the B&G dies, or else disconnect the B&G and keep it as backup, but there might be occasions it would be nice to be able to use either one.

I only have 3.5" vertical clearance under a floorboard in the logical spot to place the new transducer, so don't think I can go with an internal surface mount which would have been the simplest solution. I'm also trying to find a transducer that might fit the B&G thru-hull and hook up to the Lowrance CP, but I don't believe there are any possibilities there either.

Thanks