I've always read that for a unit to be the most accurate the puck needs to be mounted as close to the transducer as possible. I just mounted an 899 on the front of my allison xb 2003. Not wanting to drill any new holes and not wanting to take up floor space I mounted the puck on the trolling motor bracket. I figured if it didn't work out I would just connect the front graph to the rear one and be done with it.
When I tried it out it worked like a charm, puck is out of the way and still reads just fine. Has anyone done this before?