Atlantic White-sided Dolphin
Lagenorhynchus acutus

f10 @ 1/2000s, ISO:1000, Nikon D3S w 300mm

"Atlantic White-sided Dolphin," Wikipedia, the free encyclopedia. The species is endemic to the North Atlantic Ocean. Areas of particularly high population density include the shores of Newfoundland and Cape Cod, the triangular area of sea between the United Kingdom, Iceland and Greenland and the North Sea. The total population is believed to be 200-300,000 individuals.
Offshore, east of Nantucket, Massachusetts