I have an indian river otter. It is a good little canoe. I attached a 45 minn kota on the back and use a 120ah lifepo4 battery. I have been all over the state of Florida in this thing with my dog, my lady, a full cooler, and a survival bag. It is comfortable and sturdy to the point where I can literally stand on one side and not even come close to flipping the boat. I also have a 13’ mohawk that has a stern keel and a round bottom. The mohawk tracks and maneuvers better, but the comfort and stability of the otter cant be matched. Unless of course you have a dolphin canoe, which are the best in my opinion.
Keel!
Block coefficient. Period. Neither of the other choices matter. The lower the coefficient the better the tracking.
The original use of a tunnel hull was to lower the wetted surface under power with the full rigidity of a hull.
Then people like Shoal Cat made then as a fishing skiff. Incredible stability and great planing.
I would guess the Otter is hogged out for stability. It adds extra hydrogen bonding in the center and that would hold surface tension better. It won’t do a thing for tracking, I don’t think that little keel will help tracking either.
Work on your paddling technique, it will be worth it.