If I read this right he means a flat edge on the paddle, like maybe 1/8" to 1/4" thick, from the tip up about 1/3 the blade length?

I think you will find that it ventilates a lot more than a rounded edge. THe sharp edges give the veltilation a place to start, and it goes down the whole edge. But I could be wrong, give it a try and you can always round the edges off quickly with some sandpaper.

Ive found that generally, sharper edges make nice paddling, but can be uncomfortable when using an extended grip. Thicker rounded edges are more comfortable to grip, and they are nicer for rolling, but pick up more water when paddling and dont slice as well for sculling. By 'sharp' I mean, less than 1/8" and rounded over. ANd 'thick', I mean about 1/4" or maybe a little more. So much depends on what you are comfortable with, and how you want to use it.

: 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?