My guess is that
Posted by: pblanc on Dec-11-12 11:27 AM (EST)
Rich is talking about ZRE Power Surge paddles which have a rather extreme amount of relief in the upper blade area, so much so that the upper blade is barely wider than the shaft.
If so, the question makes sense to me. It would seem that ZRE considers the relieved portion to be "blade" since, if I remember correctly, on their bent shaft versions of the Power Surge the angle occurs at the point at which the highly relieved blade meets the oval shaft.
But if you have a zero degree Power Surge I guess you would have the option to decide whether you want to submerge all of the "blade" or not. I have never used one with zero degree bend so I don't know what I would do. Obviously, if you chose to submerge all, or nearly all of the highly relieved part then you would count it as blade, if not then you would count the part you don't sink in the water as shaft.
I suspect I would choose to use the paddle in such a way that the relieved part would fit best against the curvature of the hull of the canoe.