IIRC, several original kayak-using People used single-bladed paddles in their kayaks, as well as with the open-deck umiaks. Don't have my copy of "Bark Canoes & Skin Boats of North America" (Chappelle, et al) handy to list the specifics, but it was done. And with a good-tracking boat, there's not too many reasons NOT to use the single-blade.

Just don't call your decked boat a "canoe" unless you're in England, Australia, or someplace like that where the open birchbark-style boat is a "Canadian canoe" rather than just a "canoe". (Gotta be careful about the term "fanny pack" for luggage-on-the-belt too. I understand the Brits & Aussies use "fanny" to mean specialized female anatomy, not everyone's posterior. Ain't language wonderful?)

Val