Looking for recommendations on new unit to replace my old Lowrance 3500. I'd like similar size and style as keeping it in existing location. Also, since old transducer can't be used or reached without cutting boat apart Formula support suggested putting new thru hull sending unit under cabin step. Any suggestions appreciated!

There is this:

Joe308,

What model boat do you have? I am adding a Garmin GPS with shoot through transducer, under the step would be easy install.

I have a Fastech 312.

Responded in your other thread, Josh.

In the parts diagram for the 420 and 425, there are different risers options. It would be interesting to see what the inside of the tailpipe looks like (Merc refers to it as a tailpipe). I'm voting muffler especially since she seems to sound like a Sea Ray in the videos I've watched.

I have a 353 and the choices are somewhat Limited for 3 1/8 in units. Most are big screen now. Ended up going with the Lowrance 3800 and I will be epoxying the skimmer transducer into the same spot under my step where the puck transducer was. It was very difficult to get the original one out but after much prying and banging we finally did. I spoke to Lowrance about this and they said the transducer would work as a shoot thru just with a liittle reduced sensitivity. There are also some videos online.