Can someone tell me if it hurts the transducer or the HB head unit to turn it on when sitting on the trailer at home. I would like to get more familiar with this new 899 but its too cold to go to the lake. I'd like to take the manual and get in the boat in my yard and see the unit as I read along. I read on another forum somewhere that this could damage the transducer. I don't know if they really knew what they were talking about - you can read anything. But I'd like to know for sure, so here I am, asking.