At home, a second paddle was made based on the Oregon paddle because I wanted a spare. It turned out that the paddle was a little chunkier than desired, and after some use, was planned down again, paying careful attention to the blade shape as a wing foil. The distinctive feature that makes a Greenland paddle effective is that it is a wing foil shape. The blade enters the water with the blade slightly canted forward. As the blade stroke moves the paddle deeper into the water, it tends to fly down. It is the downward "lift" (lift being down and forward in this case) that you pull against. This is like pulling against the lift of a wing, but upside down. The wing flies down, you pull up.

The wing foil shape is necessary to control the water vortices coming off the blade. On an airplane, excessive vortices can disrupt the airstream and cause a stall. If the wing is not "flying" it will stall. This can be emulated by trying to use a Greenland paddle like a "spoon" paddle in a low brace. Slap the Greenland against the water and it will just bury itself and not support you. In this case both edges of the paddle are in a stall with uncontrolled vortices.

A very short wing will also have excessive vortices off the tip. (Notice modern passenger jets with winglets on the tips of the main wings.) With water the density (compared to air) allows you to have a greater angle of attack before a "stall" occurs on your blade. In airplanes, the most efficient wings are very long and thin, described as having a high aspect ratio. That is the shape we want our paddles to emulate. We can't make them like glider wings because we still have to maneuver them, and they need some strength to maintain stiffness and not break. And since the paddle is used in all orientations, the blade shape must be symmetrical on top and bottom. Actually there is no top or bottom on a Greenland paddle. So the guiding principle in carving Greenland paddles is make them similar to a 'symmetrical high aspect ratio' wing.