Alex Mustard / 2020VISION / Common sunstar (Crossaster papposus), brittlestars and sealoch anemones form a typical undersea community in a Scottish sea loch, Loch Duich, Ross and Cromarty, Scotland, UK, April 2011

Juergen Freund / Scientists on the Undersea Explorer research vessel testing a coconut rattle to attract sharks. Queensland, Australia. John Rumney.

Tui De Roy / Galapagos Sea Lion (Zalophus wollebaeki) pup cavorting in undersea cave, Seymour Island, Galapagos Islands, Ecuador

David Fleetham / Painted frogfish (Antennarius pictus) with first dorsal spine and lure extended to attract prey. Dumaguete, Philippines.

Michael Pitts / Diver examining the sandstone structure of the Yonaguni undersea monument, Yonaguni, East China Sea, Japan. February 2014.

Michael Pitts / Diver examining the sandstone structure of the Yonaguni undersea monument, Yonaguni, East China Sea, Japan. February 2014.

Michael Pitts / Diver examining the sandstone structure of the Yonaguni undersea monument, Yonaguni, East China Sea, Japan. February 2014.

Philip Stephen / Dive support vessel "Normand Pioneer" undertaking subsea operations on the North Sea, September 2009.

Juergen Freund / 13 captured Chambered nautilus {Nautilus pompilius} in an ice box on board 'Undersea Explorer'. They will be measured, recorded and released in the reef. 2007

Juergen Freund / Guests help out 'Undersea Explorer' marine biologist Qamar to engrave, photograph and measure caught Nautilus for research, Queensland, Australia, 2007

Juergen Freund / Guests help out 'Undersea Explorer' marine biologist Qamar to engrave, photograph and measure caught Nautilus for research, Queensland, Australia, 2007

Juergen Freund / Shell of a caught Chambered nautilus {Nautilus pompilius} being engraved with a number for research onboard the 'Undersea Explorer', Queensland, Australia, 2007

Juergen Freund / Researcher Jaap on board research boat 'Undersea Explorer' bringing up two caught Chambered nautilus {Nautilus pompilius} Queensland, Australia, 2007

Juergen Freund / Dr. Peter Ward observing Chambered nautilus {Nautilus pompilius} specimen with attached radio transmitter, onboard the 'Undersea Explorer' research boat, Queensland, Australia, 2007

Juergen Freund / Research / Diving boat 'Undersea Explorer' with guests and crew at the bow of the boat in Cod Hole, Great Barrier Reef, Queensland, Australia, 2007

Juergen Freund / Split level of research / diving boat 'Undersea Explorer' with free diver exploring the coral reef, Pixie Pinnacle, Great Barrier Reef, Queensland, Australia, 2007

Juergen Freund / Research / Diving boat 'Undersea Explorer's back dive deck with divers, Great Barrier Reef, Queensland, Australia, 2007

Juergen Freund / Nautilus being measured upon the research vessel Undersea Explorer, Queensland, Australia

Juergen Freund / Nautilus onboard the Undersea Explorer research vessel with three scientists in the background, Queensland, Australia

Juergen Freund / Scientists engraving tracking numbers on nautilus onboard the research vessel Undersea Explorer. Queensland, Australia

Juergen Freund / Group of Nautilus onboard the Undersea Explorer research vessel, Queensland, Australia

Juergen Freund / Scientists on the Undersea Explorer research vessel testing a coconut rattle to attract sharks. Queensland, Australia

Juergen Freund / Scientists on the Undersea Explorer research vessel testing a coconut rattle to attract sharks. Queensland, Australia. John Rumney

Juergen Freund / Scientists on the Undersea Explorer research vessel with a Nautilus. Queensland, Australia

Juergen Freund / Dr Billy Sinclair engraves tracking number on a nautilus onboard the research vessel Undersea Explorer. Queensland, Australia

Juergen Freund / Undersea Explorer's crewwith grey reef shark (Carcharhinus amblyrhynchos) to collect tissue samples. North Horn, Queensland, Australia

Juergen Freund / Undersea Explorer's crew baiting grey reef sharks (Carcharhinus amblyrhynchos) to collect tissue samples. North Horn, Queensland, Australia

Juergen Freund / Snorkler on tow line, behind 'Undersea Explorer' boat, watching Dwarf minke whale {Balaenoptera acutorostrata} Queensland, Australia

Juergen Freund / Dwarf minke whale {Balaenoptera acutorostrata} passing hydrophone of the boat 'Undersea Explorer' Great Barrier Reef, Queensland, Australia

Juergen Freund / Susan Sobtzik working on her days's research onboard the Undersea Explorer, Queensland, Australia, 2006

Juergen Freund / Researcher Susan Sobtzik hanging on a 'minke line' with video recorder, on board the boat 'Undersea Explorer' Queensland, Australia, 2006

Juergen Freund / Split level of Dwarf minke whale {Balaenoptera acutorostrata} and tourist whale watching boat 'Undersea Explorer' Queensland, Australia 2006

Tui De Roy / Galapagos Sea Lion (Zalophus wollebaeki) pup fishing amid school of striped snapper in undersea cave, Seymour Island, Galapagos Islands, Ecuador

Norbert Wu / Undersea desert, shallow sand dunes underwater, Grand Cayman, Caribbean

Norbert Wu / Undersea desert, shallow sand dunes underwater, Grand Cayman, Caribbean

Norbert Wu / Cavalla (Caranx sp) school and other pelagic fish surround undersea pinnacles, pelagic fish are rarely seen near land, Revillagigedo, Mexico

Tui De Roy / Galapagos Sea Lion (Zalophus wollebaeki) playful pups cavorting in undersea grotto, James Bay, Santiago Island, Galapagos Islands, Ecuador

Norbert Wu / Sea Star (Odontaster validus) group feeding on Algae, Weddell Seal (Leptonychotes weddellii) near surface of undersea ice crack, Antarctica

Doug Perrine / Whitetip reef shark (Triaenodon obesus), being cleaned by endemic Hawaiian cleaner wrasse, (Labroides phthirophagus) while resting in undersea cavern, Touch of Gray dive site, North Kona, Hawaii, Paci...

Tui De Roy / Bonito (Sarda orientalis) shoal swimming past the undersea base of Darwin's Arch. Darwin (Culpepper) Island, Galapagos.

Tui De Roy / Bonito (Sarda orientalis) shoal swimming past the undersea base of Darwin's Arch. Darwin (Culpepper) Island, Galapagos.