> long paddle

Comparing the length of the paddle to the paddler, it would seem to be about 12 feet long (the paddler is probably closer to 5' than 6'.) Pretty long. The ones I saw at the Canadian Canoe Museum were 10' long, and narrow. The guide commented to me that the design was constrained by the available materials, as there are no trees in Greenland. With that in mind, the long narrow paddle is an ingenious solution to the problem of not being able to make shorter, wider paddles. This shape probably isn't the best, just the best they could do with what was available. Besides, you couldn't use a wide paddle blade as a spear, as the Greenland Eskimos used theirs.

The short Greenland paddle may have special advantages over the longer one. I have read it referred to as a "storm paddle", and it seems to me it would be advantageous in negotiating narrow passages (perhaps between ice floes!)