if i epoxy my transducer to the hull will it shoot through the epoxy/ply glass, its supposed to be mounted on the back of a hull but this isnt convenient of a 40ft cat si im looking at epoxiying it into the boat hull
Correct - in your case, the ply is just timber and as such, contains a fair amount of air.
All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find it was vanity: but the dreamers of the day are dangereous men, for they may act their dreams with open eyes, to make it possible. T.E. Lawrence