Alex Mustard / A fisherman swims down to touch the statue of Christ Of The Abyss (Cristo degli abissi) for good fortune, in the Marine Protected Area of Portofino (Area Marina Protetta, Portofino), Liguria, Italy. M...

Michele Westmorland / Underwater Sculpture Gallery off Molinere Point, created by Jason de Caires Taylor. Colonised by sea life, Grenada, West-Indies, Caribbean, May 2009. No release.

Doug Perrine / Shimmering heat waves distort the image of diver as he samples erupting pillow lava at ocean entry of Kilauea Volcano, Hawaii Island.

Doug Perrine / Diver shaping erupting pillow lava by hand to form underwater lava sculptures at ocean entry from Kilauea Volcano, Hawaii.

Doug Perrine / Diver sampling red hot pillow lava at underwater eruption of Kilauea Volcano, Hawaii.

David Fleetham / Split-level image of swimming pool and ship / restaurant named The S/V Mnuw (Sea Hawk) at the Manta Ray Bay Hotel on the island of Yap, Micronesia. September 2007.

Alex Mustard / Statue of a mermaid 'Amphitrite', placed underwater on a coral reef as an attraction for divers. George Town, Grand Cayman, Cayman Islands, British West Indies. Caribbean Sea.

Olga Kamenskaya / Painting of Baikal seal on Baikal ice, painted underwater, Lake Baikal, Siberia, Russia. March.

Alex Mustard / Underwater photographer Alex Mustard taking a self-portrait with a friendly young grey seal (Halichoerus grypus). Farne Islands, Northumberland, England, British Isles. North Sea. Model released.

Alex Mustard / The Guardian Of The Reef Statue, with diver, Lighthouse Point. Grand Cayman, Cayman Islands, Caribbean Sea.

Alex Mustard / The statue of Christ Of The Abyss (Cristo degli abissi) in the Marine Protected Area of Portofino (Area Marina Protetta, Portofino), Liguria, Italy. Mediterranean Sea. This was the world's first under...

Claudio Contreras / Submarine statues at the MUSA Cancun Underwater Museum, a conservation project to promote the growth of coral. Isla Mujeres, Cancun National Park, Caribbean Sea, Mexico.