I've used the steel drums up in Alaska. I don't recommend them for canoe trips. They are heavy and unwieldy, though effective. They'll also beat up your boat unless you have some protection. Multiple smaller units (like a BearVault) are much easier to manage. I've used Garcia canisters on 30 day trips up there--sort of a pain but imminently useable (5 canisters per person)-just stuff them in a pack.