David Fleetham / Hawksbill Turtle (Eretmochelys imbricata) and a shoal of fish near sea surface. Tubbataha Reef, Philippines.

Solvin Zankl / Baby Olive Ridley sea turtle (Lepidochelys olivacea) struggles against the swell to swim away from the beach where it hatched, Ostional, Costa Rica. October. Winner of the Underwater category of the G...

Alex Mustard / Southern stingray (Dasyatis americana) two swimming over sand bar, under stormy sky. Grand Cayman, Cayman Islands. British West Indies.

Doug Perrine / Dugong or Sea cow (Dugong dugon) split level view, Calauit Island, off Busuanga, Calamian Islands, Palawan, Philippines.

Alex Mustard / Split level image of Leather corals (Sarcophyton sp.) flourishing in shallow water close to uninhabited coral islands. Misool, Raja Ampat, West Papua, Indonesia. Ceram Sea. Tropical West Pacific Ocean...

Tui De Roy / Marine iguana (Amblyrhynchus cristatus), Punta Espinosa, Fernadina Island, Galapagos

David Fleetham / Humpback whale (Megaptera novaeangliae), mother and calf swimming just below surface in front of the West Maui Mountains. South of Lahaina, West Maui, Hawaii.

David Fleetham / Whale shark (Rhincodon typus), a commercial encounter for tourists with feeder above on canoe. Oslob, Cebu, Philippines. April 2017.

David Fleetham / Blacktip reef shark (Carcharhinus melanopterus) swimming just below surface at sunset, split level view. Off the island of Yap, Micronesia.

David Fleetham / Green Sea Turtle (Chelonia mydas) below surf instructor Tara Angioletti on a stand-up paddle board off Canoe Bearch, Maui, Hawaii. Model released.

Alex Mustard / Giant mottled eel (Anguilla marmorata) in river with villagers washing clothes in background. Ambon, Maluku Archipelago, Indonesia. Banda Sea, tropical west Pacific Ocean.

Alex Mustard / American crocodile (Crocodylus acutus) reflected in the surface as it floats, Jardines de la Reina, Gardens of the Queen National Park, Cuba. Caribbean Sea.