Shoot Through Transducer

[PressureDrop]

fred, my ducer is a transom mount that just sits in the bilge. no silicone it just sits up against the center stringer.
plus side is no holes in the transom.
minus side is it does not read very clearly past 300'. i will pick up depth all the way out to 1000', but not a with a clear picture of bottom, however the picture is perfect (great bottom definition) all the way out to 200'+ so for the reefs in 60-100' it works great. sounds like it would work for your application if its not too late