It looks like something out of Dr Who – but the monstrous apparition which is one of the highlights of a new exhibition at the National Maritime Museum is a copy of the world’s oldest working diving suit.

A replica of the 18th century outfit, made from stitched calfskin like the original, is on loan from the Raahe Museum, Finland.

It was tested in 1988, when a diver remained (reasonably) comfortably submerged for a number of hours.

Oceans of Discovery, sponsored by the Friends of the NMM to celebrate their 21st year of support, tells the story of scientific exploration above and beneath the waves.

It includes remarkable tales of some of the world’s most famous explorers, including Captain Cook, Sir Ernest Shackleton and Jacques Cousteau.

The exhibition is part of the Museum’s Planet Ocean initiative, which explores the past, present and future of the oceans, linking the three Greenwich sites (Museum, Royal Observatory and Queen’s House) through the themes of sea, ships, time and the stars.

It covers developments in navigation from the Vikings and early Polynesians onwards, outlining the history of human attempts to map the world and chart its oceans.

Particularly fascinating is a replica map of the Marshall Islands, of a kind apparently employed by Polynesian navigators for thousands of years.

Made of interwoven, twisted slivers of wood representing significant ocean currents, the islands are denoted by cowrie shells.

A European historic perspective is given by an unsigned world map on vellum, dated 1529, which is believed to be the work of the Florentine cartographer Girolamo da Verrazano.

Verrazano and his brother Giovanni explored the east coast of America between 1524-28. The unfortunate Giovanni was killed and eaten by cannibals he had mistaken for being friendly in the West Indies – an event his brother witnessed.

Diving history is illustrated through several odd contraptions, from early submersion suits like the one pictured to modern, state-of-the art technology.

There are a number of activities for children, including eye-level peepholes set into the walls under the exhibition cases and the opportunity to examine the replica of Shackleton’s boat James Caird, used in the Channel 4 television production Shackleton, starring Kenneth Branagh.

They also get a chance to design their own deep-sea fish.

Museum Director Roy Clare said: “Oceans help us to breathe; the seas are literally vital to us.
“Oceans of Discovery respects the marine environment and examines mankind’s approach to sea-borne exploration.

“This exhibition will appeal to visitors curious to know more about some celebrated explorers, to understand their equipment and to learn of the ideas that have enabled them to push back the frontiers of the world’s oceans, enhancing our understanding of our life-support system.”