Help with transom mount transducer placement

[Fr. Frank]

Mount in so that the bottom of the 'ducer is 1/8" below the hull, with a slight angle forward. I recommend just inside of the inner hard chine, so that at higher speeds it will still get a reading.

Note, however, that at speeds above 35 mph, even the bottom hard chine can catch air. When my Humminbird Matrix does that, I don't get a good reading again until I slow down below about 22-23 mph.

A shoot-thru hull transducer avoids that issue, but then you gotta put in faring blocks to get it vertical and all kinds of other stuff.