Michael Daly wrote:

Light also means that it will transfer more of the force in bending the
hull to the gunwale. I've seen an ash gunwale snap in easy WW. The
Kevlar canoe was empty but for two paddlers and when they pounded over
a small haystack, the gunwale went into compression and popped.
I'd guess that a vinyl gunwale would have handled it; aluminum, maybe.
The problem is that the only way out for the gunwale is to buckle and
that may permanently deform the aluminum gunwale (unless, of course
it manages the load without buckling).

I certainly wouldn't recommend an ultralight Kevlar canoe in WW. The
hulls of those are too flimsy to take the pounding of a few haystacks.

The problem with the word "light" is that it doesn't quantify anything.
One light canoe might handle it, another not.

Mike

That gunwale failure wasn't due to the hull design - it was a bad
gunwale. I've paddled quite a lot of "heavy water" class 3 in my 23 lb
kevlar boat with no problems. It's all how you do it. Because the boat
is so light, I rarely hit rocks anyway.

The good part is that (contradicting a previous post) you can definitely
feel the difference between a 25 lb. boat and a 40 lb boat. It's not
the total weight - it's the polar moment of inertia that you can feel.
And that's roughtly proportional to the boat's weight - since the
paddler is in the center of the boat, (s)he adds little to the total.