Dall's Porpoise

Dall's porpoise is a robust North Pacific porpoise with a small head, no beak and a broad-based triangular dorsal fin. Its striking black-and-white pattern places a large white flank patch against an otherwise dark body, while the trailing edges of the dorsal fin and tail can be pale. Adults can reach roughly 2.3m and about 200kg (Wikipedia, general species account).

The species inhabits cool, deep waters of the North Pacific and adjacent seas. It is among the fastest small cetaceans and often produces a distinctive fan-shaped spray, called a rooster tail, when travelling rapidly at the surface. Dall's porpoises eat schooling fish and squid, commonly occur in small groups, and sometimes approach fast-moving vessels to ride their bow waves (Wikipedia, general species account).