An Enigma machine — the German encryption device used by Nazi forces to send secret message during World War II — has been recovered from the Baltic Sea.
Divers recovered the device at the bottom of Gelting Bay, on Germany’s northern coast, while working to remove abandoned fishing nets that threaten marine life.
Designed shortly after WWI by the engineer Arthur Scherbius for commercial usage, the cipher engine was adopted by many national governments and militaries.
The portable device is best-known for its use by the Axis powers to encode military commands, for safe transmission by radio, as part of their rapid ‘blitzkrieg’ strategy.
Enigma featured a number of wheels, which together formed an electric circuit that repeatedly scrambled an entered character — and reconfigured after each letter.
German military models — made more complex through the addition of a plugboard, for added scrambling — and their codebooks were highly sought by the allies.
Codebooks contained the daily instructions for how operators should pick and set the machine’s code wheels and plugs which encoded the messages.
Understanding the principles behind the machine and its daily code changes allowed experts at Bletchley Park to learn to decrypt Nazi radio transmissions.
At their peak, the Allied forces decoded some 3,000 German messages a day — notably helping the admiralty track down U-boats during the Battle of the Atlantic.
The find was a discovery like no other, said Gabriele Dederer of the World Wide Fund for Nature (WWF), which hired the divers for the marine conservation effort.
‘The WWF has been working for many years to rid the Baltic Sea of dangerous ghost nets,’ she added.
Abandoned or lost fishing nets, known as ghost nets, represent a deadly trap for fish, marine mammals and sea birds — and are a form of underwater pollution.
‘We regularly find larger objects, on which the nets get tangled underwater. Such so-called “hook points” are often tree trunks or stones,’ Ms Dederer said.
‘The Enigma is by far the most exciting historic find.
The device was found on the seabed after Submaris — a company based in Kiel — used side-viewing sonar technology to identify the net that it was caught in.
Submaris diver Florian Huber said that the machine was most likely sent to its watery resting place in May 1945.
This month saw 47 German U-boats scuttled in Gelting Bay by their crews, who were determined not to let the vessels fall into the hands of the Allies.
‘We suspect that our Enigma went overboard in the course of this event,’ Mr Huber explained.
Copies of the Enigma machine are now ‘extremely rare’, Mr Huber noted, with ‘only a few specimens […] available in German museums’.
‘As an underwater archaeologist, I have already made many exciting and strange finds,’ he continued.
‘However, I didn’t dream that we would once find an Enigma machine.’
‘It was a grey November day I will not forget so soon.’
The newly-discovered Enigma machine has now been sent to Museum of Archaeology in Schleswig, where it will be preserved and studied further.
The WWF — which has released an app showing the location of suspected ‘ghost’ nets — has asked divers making use of the data to respect any historical artefacts they might uncover as a result.
‘Should further archaeological finds come up, we would like to point out that there is a legal obligation to report them, as this could be underwater cultural heritage,’ commented Ms Dederer.