Followup. Purchased the si unit and installed it on the trolling motor. I've just now gotten around to installing a second transducer on the transom. Bought another power cable and fixed a mount at the console. I still use the same gps puck and simply move it to the rear when hooked up at the console and move it to the bow when hooked up at the trolling motor. Works great and a lot less cost than two units.