To ensure used canoes are safe, place the canoe on a flat surface, and examine it. Avoid canoes that are twisted, bowed or warped. Safe canoes are symmetrical, touch the ground evenly along the keel, have no visible damage and are not discolored.
To examine the keel, place the canoe on a flat surface, and examine the area where the canoe touches the ground. Avoid canoes that are bowed or raised unevenly along the keel, or along the area where the canoe meets the ground.
Stand in front of the canoe, and examine the overall symmetry of the boat from its center point. Twisted, or asymmetric, canoes are difficult to control in the water and aren't considered safe.
Examine the inside of the canoe, and avoid purchasing canoes that are cracked or have other signs of damage where the seat meets the sides of the canoe. Delamination, which is identified by patches of cloudy discoloration, worsens when the canoe is exposed to water, and it isn't considered safe.
If the canoe is patched, the edge of the patch should be smooth and free of hairline cracks or other damage. Canoes that are stored directly in the sun for long periods of time aren't considered safe, as UV damage can occur.