: A person whose opinions I respect, told me that my greenland paddle would
: work better if the outside edges of the blade were square rather than
: rounded. He suggested modifying my paddle for the last third or so of the
: blade. Don't do all the blade because the square edges are not comfortable
: when you slide your hands around during paddling.

: I have to make some changes anyway, so incorporating this is not a biggie.
: What is the advice/experience out there?
This is just my opinion. I think that standard and/or euro paddles are more efficient when the edges are relatively sharp...ie: square. How sharp the edges should be is another question. However...when you get to wing paddles which incorporate lift (as well as drag) through the shape of the paddle your're talking about a different donkey. The shape of the paddle directs the flow of water which creates "lift". I've done a lot of research into this because I like to re-invent the wheel once every two years. It's been done before, but I can't keep from thinking that just maybe...maybe...there is some little quirk everybody is missing that I'll discover. Anyway...I consider greenland paddles to be a type of wing paddle. If you've ever researched aerodymanics then you'll discover that greenland paddles have a lot in common with supersonic wings...and acrobatic wings. The greenland paddle does create lift (and the ever present drag) through the shape of the paddle AND the angle at which it is held...or stroked through the water. The flow of water in front of the paddle creates drag, the flow of water around the back of the paddle also creates "lift" through the redirection of water a bit forward as it leaves the back edge of the paddle. The flow of water around the back edge of the paddle is a phenomenom called...I think...the coanda effect. Anyway...a square edge on a "wing" type paddle is not the best shape for creating the proper flow of water...or air...same difference. I do believe that there is room for more experimentation with paddles. How complicated can a paddle be? Just as complicated as are airfoils (wings). You can actually fly a plane with a wing in the shape of a barn door..what they call the barn door wing. Hmmm...stands to reason. BUT...you can fly more efficiently with other shapes. A one percent improvement in paddles would be huge. I guess you can tell that I like thinking about and experimenting with weird things. Most of my paddles look pretty clunky...but someday...maybe...I'll the the einstein of paddle design. (How do you spell that?). Einstein is wrong about the theory of relativity anyway. Did I ever tell you that it is not gravity that keeps us standing on earth...but the weight of the air pushing down on us? Another little theory I have....