i see quite a few posts complaining about the weight of certain canoes while portaging. but, no mentioning of the canoe weight while paddling. as an example the weight of the mad river solo freedom has been mentioned as to heavy to portage long distances but it still seems to get rave reviews on performance, with no mentioning of it as too heavy/sluggish. so, how much does canoe weight affect performance vs design? in other words when does canoe weight over-take design making it sluggish or affecting performance enough making it a "pig" vs "a dream to paddle".
For displacement boats powered by paddle oars or propeller the weight of the boat makes very little difference in speed. Weight can make a difference in how a boat feels. Light boats get up to speed quickly and are more easily slowed down by adverse winds and waves. heavier boats carry though waves a better sometimes making it easier to maintain a given speed.
The biggest difference in boat speed and feel will be due to the hull shape and size.
Light boats feel much easier to throw
around in whitewater. I have a MR Guide, and it is light enough for what it can do in whitewater. It is a bit limited by its relatively sharp ends. My MR Synergy is about the same weight, but more highly rockered. Because the Synergy hull allows fast spins (and also accelerates faster than the Guide) the weight of the Synergy hull is much more noticeable to me.
At the lower limit, I have a Dagger Zealot c-1 at 23 pounds, and a Millbrook Wide Ride C-1 at 28 pounds. These feel MUCH easier to throw through sudden maneuvers than, say, a 40 pound plus Dagger Atom or Cascade C-1.
Total weight of boat +paddler+gear
is what determines how deep the canoe sits in the water and how much displacement and hull drag you have to paddle against. With a light solo boat as mentioned in the above post, the difference between two hulls can be felt by the paddler. Mostly in the case of the whitewater boats because of the lighter ends and less polar momentum. With tandem canoes, even when paddled empty, the total weight of the two paddlers, gear, and boat does not change much going from a lightweight Kevlar or Carbonfiber layup to a heavy Royalex hull. Two 150# paddlers + 25# for gear(paddles, PFDs,water) + 35# for a lightweight tandem = 360#. Going to a 70# Royalex version of the same hull would up the total weight to 395# and make maybe a half inch difference in draft if the canoe was very narrow. Not very noticeable in paddling. Add expedition baggage and make the canoe a big tripper and the difference is even less. The Royalex boat will paddle slower due to its blunt bow, but not from its heavier weight.
Hope this helps,