Alex Mustard / A diver explores Silfra Canyon, a deep fault filled with fresh water in the rift valley between the Eurasian and American tectonic plates at Thingvellir National Park, Iceland. May 2011. In this phot...

Franco Banfi / Scuba diver exploring El Eden cenote. Quintana Roo, Yucatan Peninsula, Mexico.

Pete Oxford / Whale Shark (Rhincodon typus) with scuba diver, Cenderawasih Bay, West Papua, Indonesia.

Franco Banfi / Scuba diver photographing Great white shark, (Carcharodon carcharias) from cage. Guadalupe Island, Mexico, Pacific Ocean. September 2011.

Franco Banfi / Scuba diver photographing Great white shark, (Carcharodon carcharias) from cage. Guadalupe Island, Mexico, Pacific Ocean. September 2011.

Franco Banfi / Scuba diver and Tiger shark (Galeocerdo cuvier) Northern Bahamas, Caribbean Sea, Atlantic Ocean. March 2009.

Franco Banfi / Scuba diver and Humboldt squid (Dosidicus gigas) at night off Loreto, Sea of Cortez, Baja California, Mexico, East Pacific Ocean. August 2007.

Franco Banfi / Scuba diver with Devilray (Mobula tarapacana), Ambrosio dive site, Santa Maria Island, Azores, Portugal, Atlantic Ocean

Alex Mustard / Diver exploring the wreck of HMS Scylla, which is colonized by Dead man's fingers (Alcyonium digitatum). Whitsands Bay, Cornwall, England. UK, July.

Alex Mustard / Nassau grouper (Epinephelus striatus) watched by a diver on a coral reef. San Salvador island, Bahamas. Bahamas Sea, Tropical West Atlantic Ocean.

Alex Mustard / Diver swimming over the stern gun turret of the 330ft long Russian frigate 356, the "MV Keith Tibbetts". The ship was built in 1984 and sunk in 1996. Buccaneer Reef, Cayman Brac, Cayman Islands. Carib...

Pascal Kobeh / Giant clam (Tridacna) on 'Lotus' artificial reef, built in 2001 with a steel frame using mild electric currents to encourage coral growth, with diver in the background. Vabbinfaru Island in North Male...