Newf, works great for trolling! I can get my speed down to 1 mph, I did my test runs in the Columbia river with a current flow of about 3 mph. The rudder on the R-21's work great for control even at very slow speeds. Some problems that I've had with my set up, the motor wants to turn and the bolt to tighten up the tension is useless, this was fixed with a bungee cord. The motor bracket was given to me, and now I know why! It will not stay locked in the elevation selected unless zip-tied, will be replacing. My auto throttle workers great! Just have to remember to turn power on to the receiver which I wired in to the starboard down rigger. I went with a long shaft sail-pro with a a 6 or 7 amp charging system, my thinking this would keep my house battery charged during long days on the water with out the main engine on, as far as the long shaft, it was not needed with an adjustable mount.
I made my bracket so it attaches to the swim platform and the tie-down eye. I cut a cap to run the fuel line and electrical wires through, this keeps everything out of the cockpit. I have some pictures in my album but if you have any questions just PM and will try to help. You have some really nice pictures of fish you've shared, good luck hope to meet up with you someday as you just fish on the other side of the pond from me, obviously the side with bigger fish! Bob