Humpback whale (Megaptera novaeangliae) surfacing in the Weddell Sea near the Antarctic Peninsula, Antarctica, Polar Regions

Tall dorsal fin of a Finback whale (Balaenoptera physalus) which is located far back along the dorsal ridge. This prominent feature is often used for identification. St. Lawrence estuary, Canada

Male Killer whale (Orcinus orca) with dorsal fin flopped to one side. Snaefellsness Peninsular, Iceland

A young humpback whale calf (Megaptera novaeangliae) tail-lobbing in the AuAu Channel between the islands of Maui and Lanai, Hawaii, USA

The transient Orca (Orcinus orca) pod, Cape Strait, Southeast Alaska, USA, Pacific Ocean

Minke whale (Balaenoptera acutorostrata). Damage to dorsal fins is often used for photo-identification purposes but even simply the shape of a 'clean' fin such as this may be identifiable. Hebrides, Scotland

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

Humpback whale (Megaptera novaeangliae) in the AuAu Channel between the islands of Maui and Lanai, Hawaii, USA

Adult humpback whale (Megaptera novaeangliae) fluke-up dive in the AuAu Channel between the islands of Maui and Lanai, Hawaii, USA

Adult humpback whale (Megaptera novaeangliae) fluke-up dive in the AuAu Channel between the islands of Maui and Lanai, Hawaii, USA

humpback whale tail fin or fluke of diving whale above sea surface water running off fluke in front of mountains at sunset cetacean cetaceans identification profile fluke margin margins one animal only horizontal format