Very helpful, US1! I appreciate the help and now know what to expect before I make such an important cut.

Is your transducer mounted with silicone? I heard silicone will not allow a correct reading due to the air in it? I was told to use epoxy. Maybe that's what you have.

Thanks again!

Use a thick coating of vasaline on the bottom of the puck & stick it to where you think your going to epoxy it down, just to make sure it reads in that location, I read this somewhere on OSO, & it works.. so good in fact I never epoxied mine down, the vaseline holds it in place & my depth gauge works great..

I did try silicone and a bag of water when testing, and neither work. That's epoxy in the pic. It doesn't work either. :)