Calibrating my fishfinder transducer

[pschauss]

I finally got around to "installing" the transducer for my Garmin Echomap in my bilge. Following suggestions from several members here, I put it in a plastic bag filled with seawater, sealed shut with a zip tie. I placed it just aft of the cabin bulkhead. About how far below the waterline is it in that location?

The depth displayed on the Garmin screen is close to the value I get from the Humminbird unit which came with my boat but I don't know what that unit is using for a reference point.

[scenarioL113]

I do not have the answer specifically but I would say in that area there will probably be a bigger difference when on plane and when crawling.

I ran in glob of silicone last season and the unit worked pretty good. I would have some interference here and there but overall it was not bad.
This year I just bought a thruhull for it and I am happy so far with the results. Now I have accurate temperature readings as well.

I am using Garmin as well