: That's unique! Congrats on its adoption, and successful completion.
: Is it known why that shape was used? And, what's the logic of
: the strip sticking up past the skin, at the stems?

According to John Jennings (The Canoe, a Living Tradition) this shape was used in the Amur Valley Siberia and the Kutenai region of BC.

I had a theory that birch bark was difficult to get in sufficient size and other barks used instead which did not flex enough to accomodate the more familiar canoe shape. While that is true in Kutenai, I recently learned that the Amur canoes were made of birch bark. Not the most stable of canoes it seems.