I would just leave both of them on. No reason not to and its always nice to have options other than paddling, when sh!t hits the fan.
I would not put a fiberglass boat with an 80hp prop motor in the Atha.B or North Sask. rivers. That's just asking for trouble. Both rivers have sand/gravel bars and change depths quickly. You could easily end up wrecking your prop or damaging the lower leg.
Stick to lakes with that boat.