"David"
Thanks for the advice everyone... will letcha know how it goes....

- David

My experience (as if anyone cared) is that plastic faced transducers
work well in an epoxy bed, but rubber faced ones have a tendency to develop
a separation after a time, and if there is enough moisture around, may not
affect operation. But the rubber faced ones work even better in either a
liquid bath or a silicone bed.
For real fish finding, and bottom evaluation purposes, there is no
substitute for hole-in-the-bottom, or a well placed and finely tuned transom
mount transducer.
The zip-lock, water filled bag is a rewarding test method, but I always
put the transducer IN the bag. Never thought of just shooting through the
whole, closed bag! Great idea!
Old Chief Lynn