Do you know what to do if you end up in the drink unexpectedly while canoeing? Here's a way to drain your boat and get back in without having to return to shore, as long as there's another small boat or canoe close by.
First things first, always wear a lifejacket when operating a canoe, especially in cold water. Anyone, including excellent swimmers, can quickly be overcome by hypothermia, or be knocked unconcious when falling out of the boat, and a life jack will keep you above water.
First, if there's any left, take all the gear out of your boat and the surrounding water, and pass it to the good samaritans in the other boat.
Then, make sure your canoe is upside down (the hull facing upwards), and perpendicular (90 degrees) to the other boat. Swim to the back of the canoe (the side farthest from the rescue boat) and use your body to push down on the end of the craft. At the same time, have the rescuer sitting in his boat lift the other end up and across his boat. This will help break the suction and make it easier to get it out of the water.
You can now swim over to the rescue canoe and just hold on to rest while the rescue boater pulls the canoe the rest of the way out of the water and allows all the water to drain out. When finished, he can turn it back over and lower it back into the water.
Now it's up to you to climb back in without blowing it and 'swamping' the canoe all over again. It might be good to practice this before going out in the water for long fishing/camping trips.
If you don't have another boat nearby, and you're in flat (calm) water, you can always get back in the canoe, even full of water, and still paddle awash back to shore. It's slow going and very unstable, but most all modern canoes are designed to float even when full of water.