Trolling Motor on Penobscot 16

To avoid the hassle of shuttling, I’ve added a small (30 lb. thrust) trolling motor to our Royalex Penobscot 16. The idea is to motor up the river and then paddle back. The motor sits just behind the stern seat on a motor mount that places it just off the left gunwale. Got a 55 lb. battery sitting on the floor of the boat and positioned to keep the boat in trim. Problem is that, with the motor in place and running, the boat loses primary stability and becomes very tippy. The minute I remove the motor and we start paddling the stability returns. Any thoughts on what might be the cause and how to address it?? Thanks.

I used to have a Penobscot 16 and as I recall one could really feel it when the dog moved around…your boat does not have a lot of primary stability to begin with. The weight of the motor hanging off one side puts a torque on the boat and throws off the side to side balance. Two things you might try…1) think about hanging something of similar weight off the side opposite to the motor. A second trolling motor would be ideal! 2) sit low in the boat, on the floor or maybe a canoe chair that gets you a few inches off the floor but much lower than your seated position. Or kneel if you are sitting. Anything that lowers your center of gravity will make your boat less sensitive to the weight of the motor that is offset from centerline of boat.

How much of this perceived instability is associated with steering? I would expect such a problem. Most trolling motors have a shaft that is much, much longer than what’s needed for a canoe, and with the control head set to a convenient operating height, that puts the propeller on the end of an unnecessarily-long lever arm. Thus, for any thrust that’s not directed exactly forward or backward, the canoe will be “pried” into a rolling motion. Sharp turns would be the worst situation of all.

If you only use that motor on the canoe, see about making the shaft a whole lot shorter. I would expect that having the top of the propeller no more than one foot below the water’s surface would be deep enough. That should help a lot if a tendency to tip during steering action is what is troubling you (and I can hardly imagine that not being a problem).

The Penobscot has a very rounded hull bottom, which is good for overall performance but will promote “easy tipping”, in any case.