Back "in the day" I did a far amount of canoe trips in places like the Yukon and B.C. . A week to ten day ones,and sometimes we had days of rain.I would say first practice your skills at home in the rain before going out into the wilds.
Now in a canoe one can carry more than a backpacker so keep that in mind.Lighters,water proof matches in water proof containers and some dry tinder(cotten in vasealine etc.)keep it in your gear on you.Set up a tarp and build it under this.Gather up a lot of wood more than you think you need. All wood is dry on the inside, split it to get at dry side, shave off the wet outside on smaller pieces make fuzz sticks.Its kind of like painting in that you put most of the time in prep.work for the best results.

Once you got it going dry out other wood by putting it next to the fire,keep some under your tent or tarp so you have some dry wood the next day.
To recap,have many fire starters,split the wood to get at the driest part,try to do it under some sort of shelter,gather and dry as much as possible and practice at home or on local camping trips first.
But my favorite way to start a fire in the rain is with a road flare

.I have a bunch of small ones (about 6 inches)from a railroad car.These are for true emergencies only,and DO NOT take the place of learning other ways.But thats one kick ass gaint match.
