Fin Whale, Balaenoptera physalus, showing chevron marking. Seen off the Azores

Short-fin Pilot Whale, Globicephala macrorhynchus, swimming off the Azores Islands

Male Blainville's Beaked Whale, Mesoplodon densirostris, swimming off the Azores, showing typical scarring along its back

Blue whale fluking up to dive (Balaenoptera musculus) Azores, Atlantic Ocean

Short-fin Pilot Whale, Globicephala macrorhynchus, mother and calf swimming off the Azores Islands

A very rare sighting of an adult blue Whale (Balaenoptera musculus) surfacing off the western side of Spitsbergen Island in the Svalbard Archipelago, Barents Sea, Norway.

Blue Whale (Balaenoptera musculus) fluke-up dive in the offshore waters of Santa Monica Bay, California, USA.

A very rare sighting of an adult blue Whale (Balaenoptera musculus) surfacing off the western side of Spitsbergen Island in the Svalbard Archipelago, Barents Sea, Norway.

The blueish colouration pattern of Blue whales (Balaenoptera musculus) is used for photo-identification. St. Lawrence estuary, Canada

Blue Whale (Balaenoptera musculus) fluke-up dive at sunset in the offshore waters of Santa Monica Bay, California, USA.

Blue whale (Balaenoptera musculus) exhaling a cloud of tiny water droplets into the air. St. Lawrence estuary, Canada

Blue Whale (Balaenoptera musculus) fluke-up dive at sunset in the offshore waters of Santa Monica Bay, California, USA.

Blue whale (Balaenoptera musculus) surfacing with long back and characteristically small dorsal visible. West of Iceland.

Blue Whale (Balaenoptera musculus). Tail Fluke above the surface before diving, Gulf of California, Mexico.

Blue Whale (Balaenoptera musculus). Tail Fluke above the surface before diving, Gulf of California, Mexico.

Blue Whale (Balaenoptera musculus). Tail Fluke above the surface before diving, Gulf of California, Mexico.

Blue whale (Balaenoptera musculus) lunge feeding at the surface. The whale is upside down to the visible part is the lower jaw upside down. Monterey Bay, California, USA

Blue Whale, Balaenoptera musculus, surfacing off the Azores Islands