what kind of boat would depend on whether you should consider the 24v more than the 12v. glass and real heavy or tin boat. I have a 04 tracker pt175, had a MG 12v 43lb that came on the boat, that did ok, but could not really control the speed that well. Put a Terrova 55lb 12v w/48" shaft and Ipilot on it, and can maintain a steady .5 on up, what ever I feel I need or the fish want. I longline 99% and pull cranks 1%, and lots of battery left at the end of the day. If you have a big glass boat, may want to consider the 24v but I'm very satisfied with my choice.