I have 2 Minn Kotas for my drift boat, a 36lbs thrust that works good for slower rivers and a 70lbs thrust(24 volt) that I use in the cowlitz. If I was you I'd get the biggest you can get that will run on 12 volts and that should be plenty for the snohomish. Also get variable speed rather than the 5 speeds forward and 3 reverse.