The second of four German navy messages still unencrypted after 60 years has been cracked, thanks to computer users worldwide contributing run cycles to the project. 

The message was sent from U-Boat 623 which was stationed in the North Atlantic during the Second World War.

The U-Boat, captained by Oberleutnant Hermann Schrüder, served less than three months in the North Atlantic before being sunk with all hands by depth charges from a British Liberator aircraft.

"Found nothing on convoy's course 55°, [I am] moving to the ordered [naval] square. Position naval square AJ 3995," the message reads.

"[Wind] south-east [force] four, sea [state] three, 10/10 cloudy, [barometer] [10]28 mb [and] rising, fog, visibility one nautical mile."

There are still two remaining messages to be decoded. The four messages proved too tough for the code breakers at Bletchley Park as they were among the first sent on a new kind of Enigma encryption device.