While working, a diver recovered six more Enigma encryption machines from the Second World War from the Baltic Sea.
Finder Christian Hüttner reported the find from near Schleimünde (Schleswig-Holstein), the State Archaeological Office reported on Thursday.
"While looking for a lost ship propeller, I came across a heap of disposed of Enigma machines," the state office quoted the finder as saying.
"Some of them have obviously already been made unusable before they were disposed of."
He made the find at the beginning of the year, said the professional diver of the German press agency.
He did not immediately recognize the encryption machines as such because of the heavy vegetation.
On closer inspection, only brass parts could be seen.
“A couple of keys peeked out.” The Enigmas were by no means the discovery of his life: “For me, this is of no particular importance,” said the 48-year-old.
"These things will never work again."
It was only in November of last year that research divers found an Enigma cipher machine from World War II in the Geltinger Bay while searching for abandoned fishing nets in the Baltic Sea.
The rare find is currently being restored in the workshop of the Museum of Archeology at Gottorf Castle in Schleswig.
In cooperation with institutes of the Fraunhofer Society, the experts from the state office want to examine the machine more closely, for example with the help of 3D computed tomography.
Great impact on submarine warfare
According to the state office, it is still unclear how the machines found got to their place of discovery.
They should also be properly preserved.
After the work has been completed, an exhibition on the encryption machines is planned in the Museum of Archeology.
In addition, these are memorials.
According to the State Office for Archeology, an estimated 100,000 to 200,000 Enigmas were built during World War II.
There were different models.
The archaeologists assume that numerous other enigmas were sunk in Schleswig-Holstein waters.
They are part of recent German history, and their locations could provide information on the events at the end of the Second World War.
After the first successes of experts from the Polish secret service, the British mathematician Alan Turing made a significant contribution to cracking the Enigma code during the Second World War.
This had a significant impact on the submarine warfare in the Atlantic.
From then on, the British were able to "read" the encrypted radio codes on German boats - unnoticed by the enemy.