To me a double paddle for canoe has not much to do with anthropomorphic measurements. On a wide canoe you need length to reach over the sides without having to reach too far. When you reach to one side you may be bringing the offside drip ring to where it can drip into your boat or even into your lap. Don't ask how I know this.
I have a pair of paddles left over from a very old Folbot kayak. It was 36' wide and the paddles were 280cm.

: Since I know there is no shortage of opinions on this forum,
: thought I would toss out a question for some feedback...

: I'm interested in acquiring a double end canoe paddle for
: occasional use when I'm paddling one of my canoes. I've got lots
: of canoe paddles, bent shaft, straight shaft, homemade and
: storebought. I was thinking of making a double end canoe paddle
: using one of the kayak paddle plans I've seen and simply making
: a longer shaft and I have been struggling with what length. I've
: seen them from 250cm to 270cm but am uncertain what the general
: guidelines are for choosing the length on one of these paddles.
: My canoes are 33" and 36" wide respectively and I'm
: 5'11". Any thoughts on what length??

: Also, I found a used 270cm Accent nylon blade / carbon shaft on
: Craig's List this morning for $65 and am interested in this one
: if the 270cm is not too long...

: Please help me sort out what length would be good....

: Bob Beaullieu