Tony Wu / Bowhead whale (Balaena mysticetus), group socialising in shallow water, aerial view. Part of larger group of more than 50 whales congregating, Sea of Okhotsk sub-population, Russia.

Alex Mustard / Spinner dolphin (Stenella longirostris) pod socialising close to surface. Fury Shoal, Sataya Reef, Marsa Alam, Egypt.

Tony Wu / Humpback whale (Megaptera novaeangliae australis) female with suckling calf. Vava'u Islands, Tonga.

Tony Wu / Humpback whale (Megaptera novaeangliae australis) male calf playing at ocean surface after coming up to breathe. Vava'u Islands, Tonga.

Tony Wu / Sperm whale (Physeter macrocephalus), ten swimming together in gathering of more than 50 individuals. Whales with flatulence and defecating. Sri Lanka.

Jordi Chias / Humpback whale (Megaptera novaeangliae), Antarctic Peninsula, Antarctica.

Jordi Chias / Humpback whale (Megaptera novaeangliae) spyhopping, Antarctic Peninsula, Antarctica.

Jordi Chias / Humpback whale (Megaptera novaeangliae) spyhoping, Antarctic Peninsula, Antarctica.

Jordi Chias / Humpback whale (Megaptera novaeangliae) fluke Antarctic Peninsula, Antarctica.

Jordi Chias / Humpback whale (Megaptera novaeangliae) diving, tail fluke, Antarctic Peninsula, Antarctica.

Jordi Chias / Humpback whale (Megaptera novaeangliae), adult and baby at surface, Antarctic Peninsula, Antarctica.

Jordi Chias / Humpback whale (Megaptera novaeangliae) surfacing with baby and blowing, Antarctic Peninsula, Antarctica.