Michael Pitts / Diver on the wreck of the US Submarine tender USS Macaw, sunk in the World War II due to a navigation error, Midway atoll, Pacific Ocean. Model released.

Michael Pitts / Diver on the bow of U-Boat -U352. Type VIIC sunk off Cape Lookout on the 9th May 1942, North Carolina, USA, September 2013.

Michael Pitts / Diver on the conning tower of U-Boat -U352. Type VIIC sunk off Cape Lookout on the 9th May 1942, North Carolina, USA, September 2013.

Michael Pitts / Wreck of the Royal Navy 'S' Class submarine HMS Stubborn, Sunk as ASDIC target 30th August 1946, Malta

Gavin Hellier / World Ocean Museum, Soviet era submarine, Kaliningrad / Konigsberg, Russia 2008

Solvin Zankl / GEOMAR / German reserach submersible JAGO on surface ready to dive at the Sula Reef off the coast of Norway, September 2011, editorial use only. Photo taken in cooperation with GEOMAR coldwater coral research...

Solvin Zankl / GEOMAR / Submersible JAGO, preparing to dive, at the Sula Reef off the coast of Norway, September 2011, editorial use only. Photo taken in cooperation with GEOMAR coldwater coral research project

Doug Allan / Submarine surfacing through ice sheet. Beaufort Sea, Alaska, USA, March. Freeze frame book plate page 131.

Patricio Robles Gil / Submarine at surface in Avacha Bay, with Koryaksky / Koryakskaya volcano (3,456m) in the distance, Petropavlovsk, Kamchatka, Russia, September 2006

Warwick Sloss / Johnson Sea Link exploration submarine employed by NOAA Ocean Explorer, being loaded back on to its support vessel after a dive

David Shale / Johnson Sealink II submersible being lowered into the sea - one of the few craft in the world capable of reaching depths of 1,000 metres. Filming for BBC tv series Blue Planet about life in the oceans

David Shale / Johnson Sealink II submersible being lowered into the sea - one of the few craft in the world capable of reaching depths of 1,000 metres. Filming for BBC tv series Blue Planet about life in the oceans