Traditional paddlers kneeled in the canoe to keep their center of gravity low and pressed their back against the thwart for support. Thwarts were used mainly for bracing the canoe, lashing supplies or portaging – not for seating.
When European settlers adopted the use of birch bark canoes for travel in North America they were not accustomed to kneeling for long periods of time. Plank seats were developed.
Plank seats are available for canoeists who intend to use their canoe for wilderness paddling.