[PSUBS-MAILIST] sonar

I have just installed a fish-finder in the ol K-boat. it is cheap.. $160.00 canadian, almost nothing US, it looks down from the back..gives me bottom distance, and roughly the type of bottom,.hard soft etc...(grey line technology) the cable comming out of it is reasonably soft, but will not crush, and the transducer itself is very hard, and filled solid with an epoxy type substance. It should not leak at all..it is mounted just above the bottom of the sub, out of harms way.. I had a stainless through hull made, almost like Captain Nemo described, except it screws together and has a rubber seal...I am also planning on getting a second transducer, and mounting it looking forward, and having a switch inside to switch between them..