Local adaptations are common in boat design. Here is one example from North Wales:
The local sailboats have twin bilge keels to let the boat sit upright on the relatively muddy bottom when the tide goes out. In this area, the tides appear to be fairly large - on the order of 6-7 meters and this works well here.
Further south in Cornwall where the bottom is a bit more rocky and the surf is a bit rougher, the bows are high with swept sheer and the working boats would be hauled up - sometimes on cribbing like the one below - on the shore above the high-tide line.
The same is true of canoes. Traditional birchbark canoes and their modern incarnations follow this rule. In the areas where the Native Americans harvested wild rice, the canoes were generally wide and flat-bottomed with specialized gunnel lines. In other areas where white-water river travel was common, more robust boats with large amounts of rocker were common. In other places large transport canoes were more useful.
In Northern Maine, the modern canoes favored by guides on Grand lake are 19-24' long square-stern canoes which can be powered by a fairly large outboard motor, are stable fishing platforms and can haul out a deer or the better part of a moose without difficulty. There is even some discussion that the hull length was an adaptation to deal with the distance between waves on the large lakes.
So, when looking around at what boat shape you might like to build, take a look around at the local canoes that more experienced paddlers find useful in your area. Still, take this with a grain of salt as your purposes may be different form their purposes and you want your boat's form to fit your function. They're more than likely well adapted for local conditions. Another excellent resource is Ted Moores book Canoecraft. It offers a much more clear and concise description of the reasoning behind canoe shapes and function than I can offer here in blog format.
Pick the adaptation that works for you!