[existentialsailor]

Will this type of depth transducer work in a fiberglass hull that has coremat in it?

Thanks.

[owlmtn]

I don''t know about coremat, but we had one in a solid fiberglass hull and tried everything suggested both by manufacturer and others. all we ever got was intermittent performance. It usually worked fine in 100 feet of water but stopped in 10 feet. we put a thruhull transducer in. Jim

[TrueBlue]

I would say your cored hull depth soundings would be erratic, intermittent and inaccurate with a "shoot thru the hull transducer". Typically (in a solid glass hull) it is necessary to have a viscous fluid or dense material between the transducer and bottom. This is usually done by inserting the transducer in a section of 3"-4" dia. pvc pipe, filled with mineral oil, glassed-into the inside surface of the lowest point in the bilge, aft of the keel.

An alternate method involves securing the transducer to the hull using a slow-set epoxy to avoid air bubbles during curing. Any air spaces or voids within the signal path will affect transmission. Therefore, the cored hull would affect accuracy. You could try filling the cored section beneath the transducer with injected epoxy resin to increase density.

You will be better served by using a bronze thru-hull. Make sure you remove a 1"-2" section of coremat around the inside perimeter of the hole after boring to minimize water intrusion. Fill with epoxy before securing the through hull fittings.

Best, Steve