Tim writes: this is a Sea Otter (Enhydra lutris) propelling itself through the calm water and creating a small wave with its head. They can weigh up to 45kg making them the heaviest member of the Weasel family. They are even heavier than Wolverine and much heavier than Giant River Otter, which is a bit longer.
Sea Otters were once abundant in the North Pacific but relentless trapping during the eighteenth and nineteenth centuries resulted in their extirpation from Canada by 1929. Their fur is the densest of any mammal on the planet which made them highly sought-after for their pelts. Between 1969 and 1972, 89 animals were reintroduced into Nootka Sound from Alaska.
I photographed this one at Zeballos on the west coast of Vancouver Island which is quite close to the original reintroduction site. The numbers here have built up impressively and the population now comprises several thousand animals. They are usually quite wary of humans, but they will allow approach to about 50m before they dive to safety.