SIXTY-EIGHT years ago some of the country's brightest minds were working side-by-side in a Buckinghamshire estate to crack the German's enigma code. The race was on for the academics to solve it and aid the war effort, and while they worked at Bletchley Park, a battle raged off the shores of Lowestoft that could help point them in the right direction.

SIXTY-EIGHT years ago some of the country's brightest minds were working side-by-side in a Buckinghamshire estate to crack the German's enigma code.

The race was on for the academics to solve it and aid the war effort, and while they worked at Bletchley Park, a battle raged off the shores of Lowestoft that could help point them in the right direction.

On May 26, 1940 the order had been given to evacuate the British expeditionary force from Dunkirk.

With ships helping to retrieve the soldiers from the French shore, the German submarine U-13 was sent to a position off the east coast to intercept the boats.

The 250 ton type IIB U-boat had previously sunk nine ships, but when she was spotted off the Suffolk coast on May 30 by lookouts onboard the anti-submarine sloop HMS Weston, her time was up.

For several hours Weston would hunt the U-boat, dropping numerous depth charges that would see water start to leak into the submarine and force it to surface for the last time at 2am on May 31.

Commander Max-Martin Schulte ordered the crew to abandon ship, but the leading engineer remained below, opening valves to flood the diving tanks and sink the ship, thus keeping it, its enigma coding machine and secret documents from falling into British hands. He did manage to escape the flooded craft, but together with the rest of the 24 crew members, he could not escape the circling British craft.

This would not be the end of the story for the U-13 however, as the Germans were so concerned that the secret of their enigma code might fall into British hands that on June, 12 1940 their air force carried out a bombing raid on the spot where they believed the submarine was lying.

Despite the raid, Skipper Lieutenant Arthur C Offord RNR of the Royal Navy Patrol Service later transported a team of Royal Navy divers to the scene to conduct a salvage operation on the wreck.

Their role was to search the U-boat for anything that might prove useful to naval intelligence, and it is believed they managed to find some code books, which were passed onto those at Bletchley Park.

An enigma code wheel was also recovered from a crew member who had forgotten to drop it into the water after abandoning ship.

Soon after the U-13 wreck was blown up as it was a danger to shipping in the relatively shallow waters off the Suffolk coast. Today the scattered remains are almost completely buried in sand.

Despite this, the Lowestoft Sub-Aqua club have dived the wreck and have retrieved some parts which will be viewable, together with a set of German leathers and transcripts of the interrogation reports, at the Lowestoft War Memorial Museum's stall during tomorrow's Fish Fayre.