Best in hull transducer

[Waltthesalt]

I'm replacing the depth sounder and want to ping thru the hull. I built a cavity filled it but the transducer I had didn't get a return.
I've got a solid hull and the best place is forward centerline where there's still considerable V to the hull, so the transducer was pinging thru the bottom of the V where I expect the fibreglass is thicker. Any ideas on a transducer that's got more power than the garden variety ones?

[jrd22]

Walt- you can test different spots by putting some mineral oil in a zip lock bag (double bag it) and laying it flat on the hull and then testing the ducer thru it (make sure there are no wrinkles or air bubbles).
Not sure what you are hooking it up to but I installed a transducer that operates at 233?kHz (avoids interference with the other depth sounder) instead of the standard 200 and it works great thru the hull to about 50 fathoms. We have ours in a well ahead of the keel just to starboard of center about 4".

[Faster]

Virtually all the transducers are made by Airmar. They have a pretty comprehensive website:

Airmar Marine Home

[chris_gee]

The reference is airmar P79. But I think you will find the max depth of f/g is 1". It also reduces sensitivity by 30% according to one source. This seems to effect the readings generally not just at depth. The sales people told me less. There is another very recent thread on this.