THEY were Hilter's biggest threat to Britain. But the first time Scots naval officer John MacDonald set eyes on some of Germany's mighty U-boat fleet, they were just a vast, impotent armada. John was one of the few witnesses to the enemy's "grey wolves" surrendering in a secret operation on the remote sea loch of Eriboll in Sutherland. On May 20, 1945, he watched in amazement from an island mail boat as the Nazi submarines slowly surfaced in the 10-mile-long loch, their periscopes displaying black flags of submission. Operation Daylight was one of the most unusual episodes at the end...