Using Humminbird 798 with only thru-hull transducer

I've added a mount for my 798 in my non-fishing boat so that I can use it for finding depth (and maybe do a little scouting for brush piles etc.) when pulling kids on tubes and skis. I've already mounted a Humminbird thru-hull transducer - my question is what settings will I need to change on the unit to use it in this fashion? Which "transducer select" choice should I make in the menu (quad beam / sidescan / universal sonar)? I've played around with it a bit and so far haven't been able to get it to work (it works fine in my fishing boat which has the side imagine transducer along with thru-hull transducer and the "Y" cable).

thanks

If the xducer installed is a 2d xducer - Set the Transducer Select menu to US2 or Dual Beam (dependent on software) ...

This shuts off the SI transmitters so that the unit is not transmitting to to open SI channels ...
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*Set the Beam Frequency selection (under the Sonar tab) to 83kHz/200kHz to get the best details and coverage combined ...
*Set Surface Clutter (under the Sonar tab) to a value that almost clears the top couple of feet of the 2d image ...
*Set Chart Speed (under the Sonar Xpress menu) to 10 ...
*Adjust Sensitivity (under the Sonar Xpress menu) up/down to get an acceptable amount of Clutter on the screen and then back it down 1 click ...

Rickie