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