Have you ever wondered why so many pictures of canoes show them, not moored to a dock in the water, but upside down on the shore?
Storing a cedar-canvas canoe in the water for lengthy periods of time will cause the canvas covering to get waterlogged. On most paddling trips, it's inevitable that some water will get into the inside of the canoe. If the canoe is not dried out properly, this water can seep through the small cracks in the planking and rot out the canvas from underneath. Hence, after a day of paddling, the canoe is pulled out of the water to a dry area and inverted upside down to drain it out and to dry out the canvas.
In between trips as well, it's good to store the canoe upside down on a canoe storage rack. This will help the canvas stay dry and keeping the wood trim off the ground will help to prevent rot. It's also important to keep store the canoe in the shade wherever possible, as prolonged exposure to UV rays from the sun will shorten the lifespan of the paint and the varnish finishes.