Alex Mustard / Southern stingray (Dasyatis americana) swimming over sand in shallow water, split level photo with blue sky and clouds. The Sandbar, Grand Cayman, Cayman Islands. British West Indies. Caribbean Sea.

Mark Carwardine / Grey whale (Eschrichtius robustus) at water surface with mouth open showing baleen plates, San Ignacio Lagoon, Baja California, Mexico

Claudio Contreras / Californian Sealion (Zalophus californianus) in kelp (Macrocystis pyrifera) forest, San Benito del Este Island, Baja California Peninsula Pacific Islands Biosphere Reserve, Baja California, Mexico, Ma...

Jordi Chias / European barracuda (Sphyraena sphyraena) and Bluefish (Pomatomus saltatrix) circling baitball of Atlantic horse mackerel (Trachurus trachurus) Formigas Islets, Azores. Finalist in the Underwater Categ...

Tony Wu / Humpback whale (Megaptera novaeangliae) adult female at rest. The tubercles on the whale's head are clearly visible, as are the barnacles (Coronula diadema), whale lice (Cyamus boopis), and hairs on t...

David Fleetham / Marine iguana (Amblyrhynchus cristatus) feeding underwater on algae. Endemic species. With Schooling black striped salema (Xenocys jessiae)(endemic species) and yellowtail surgeonfish (Prionurus latic...

David Fleetham / California sea lions (Zalophus californianus) playing in a kelp forest off Santa Barbara Island, California, USA.

David Fleetham / Three spot damselfish (Dascyllus trimaculatus) with Sea anemone home, Yap, Micronesia.

David Fleetham / Sargassum fish (Histrio histrio) at the sea surface with floating sargassum weed. Hawaii.

David Fleetham / Blacktip reef shark (Carcharhinus melanopterus) just at the surface off the island of Yap, Micronesia.

David Fleetham / Mandarinfish (Synchiropus splendidus) Yap, Micronesia.

David Fleetham / Coral hermit crab (Paguritta sp) in coral home, Yap, Micronesia. Small repro only