"hk" wrote in message
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Eisboch wrote:


The Navigator had Raytheon (Raymarine) electronics. The depth finder was
a dual freq unit and worked well in shallow water.
I had an offset programmed into it, (boat's draft was 4.5') and it very
accurately let me know just prior to going aground when it read 2.8'.
Don't ask how I know how accurate it was.

Eisboch

I have a Ray depthfinder on son of Yo Ho, attached to a through-hull (not
shoot through the hull) transducer. No offset, because it actually is
measuring the distance between the bottom of the hull and "the bottom."


Makes sense on a boat like yours. The Navigator's transducer was obviously
thru-hull amidships. The offset was to account for the rudders and 30"
diameter props.

Eisboch