Alex Mustard / Diver with friendly Nassau grouper (Epinephelus striatus) over sand by a coral reef. San Salvador island, Bahamas. Bahamas Sea, Tropical West Atlantic Ocean.

Pascal Kobeh / Diver above Cowtail stingray (Hypolophus sephen) buried in the sand, Madagascar. Indian Ocean. September 2012.

Michael Pitts / Diver examining barrel containing English East India Company coins from the wreck of the Admiral Gardner, wrecked 1809 on the Goodwin Sand, England.

Alex Mustard / A male common cuttlefish (Sepia officinalis) displays to another cuttlefish buried in the sand, while a diver photographs them, Gran Canaria, Canary Islands, Spain, May 2008, Model released

Chris Newbert / Sand Diver (Trichonotus sp) in burrow, Indonesia

Alex Mustard / Southern stingray (Hypanus americanus) swimming over sand by the stern of the USS Kittiwake (US Military submarine rescue vessel) with diver in background. Photograph was taken shortly after the wreck...

Jeff Rotman / Diver discovers Roman Amphora on sea floor. Ustica Island, Italy, Mediterranean Sea Model released.

Juergen Freund / Threadfin sand diver (Trichonotus elegans) on seabed, West New Britain, Papua New Guinea.

Juergen Freund / Threadfin sand diver (Trichonotus elegans) swimming over seabed, Lembeh Strait, North Sulawesi, Indonesia.

Alex Mustard / Diver photographing an Angelshark (Squatina squatina) as it rests on the seabed. Gran Canaria, Canary Islands, Spain.

Michele Westmorland / Sand diver / Lizardfish (Snyodus intermedius) head portrait, Dominica, West Indies, Caribbean.

Jeff Rotman / Diver searching with a sandblaster and magnetic hit during the recovery of the shipwreck "Las Maravillas", a Spanish galleon sunk in 1658, Bahamas. 1987