How far can a man travel by canoe in one day?

If a particularly fit person in a sleek unladen canoe with a high quality lightweight averaged 3knots over a total of 12 hours s/he would cover a total distance of 36 nautical miles in still water. If that person was paddling in a coastal area with strong tides such as around the British Isles and northern France where 3-4k rates are common it is not inconceivable that by planning a trip to take advantage of those tides they could more than double that distance