In the late afternoon of the 27th May the Hunt class destroyer HMS Eridge was ordered to leave her convoy escort and join a U boat hunt taking place off the Libyan coast. She soon became the only destroyer left with depth charges. Her commander Frank Gregory-Smith ordered HMS Hero away to re-arm. They settled down to a patient search. It was after midnight, in the early hours of the 28th that the U-boat was again detected. Now it became a mixture of luck and finely tuned decision making that would determine the outcome of the hunt:
All guns were trained along the bearing on which she was expected to appear. This lay in the darker sector so the destroyers would be clearly silhouetted against the moon in the southern sky. As we were expecting her to try to escape on the surface while fighting with gun and torpedoes, it would be imperitive to open fire before her own weapons could be used. Everyone was very conscious of this during the exciting, anxious wait before a dark smudge gradually materialized against the darker background.
The searchlight was immediately illuminated showing the U-Boat wallowing gently in the slight swell which was pouring off her hull and sparkling in the moonlight. Speed was increased to fifteen knots to counter a surface escape and the guns ordered to open fire. But use of the main armament was an error because the vivid flash of the four-inch guns temporarily blinded everyone on the upper deck. “Cease-fire” was promptly ordered but by the time vision was restored, the U-Boat had vanished.
Searches ahead by radar and submarine detector proved negative; neithe could propeller noises noises be heard although a look-out thought he had seen the U-Boat ahead. So speed had to be maintained while the instruments tried to verify his report. The results being negative again, the engines were stopped; at the same time HURWORTH reported she had lost contact.
The initiative had now passed to the U-Boat which might even exchange the role of hunted for hunter. She also had a choice from several additional courses of action, eitherr submerged or on the surface, and her prospects of escape would be greatly improved unless we guessed what she was doing.
If she had moved ahead, she would hardly risk turning close across the bows of either destroyer so our speed would have been sufficient to keep her in sight. She was not. But if she had remained where she had surfaced, ERIDGE would have passed her while those on the upper deck were blinded. She would then have an opportunity to move in any direction between East and West on a southerly semi-circle and that, being astern, could not be covered by our primitive fixed radar.
On the other hand the moon was now in our favour and propeller noises should be audible. But she was neither seen nor heard. So had she dived into our wake where the turbulence caused by the propellers would be making the detectors transmissions? This seemed a reasonable conclusion so I ordered both destroyers to reverse course and carry out a southerly search. How invaluable HERO would have been at that moment !
Then followed an endless, anxious thirty minutes. The detector’s transmissions flowed monotonously without any corresponding echo. Each lack of response seemed to emphasize with increasing insistence that the wrong action had been selected. If so, the U-Boat would be getting further away with every passing minute and any alternative search would be futile.
So we pressed on doggedly until, just as we were beginning to despair, the detector received the whisper of an echo at an extreme range. It could have come from a wreck or a shoal of fish but as ERIDGE drew closer, the echoes became so clear that doubt no longer existed. It was the U-Boat ! Soon afterwards, HURWORTH reported that she too had gained contact.
The U-Boat steered south for about an hour. Then she suddenly doubled back on her track and started to zig-zag in a northerly direction. But conditions were still so good that the submarine detector had no difficulty in holding her. Our main concern was still the lack of charges.
At 0400 U-568 surfaced for the last time. She came up gently and silently without any fuss. One moment the sea ahead was empty; the next she was rolling sluggishly in the slight swell. A second later she was gripped in the beam of our seaaarchlight which revealed several seamen tumbling out of the conning tower. They could have been her gun’s crew, so fire was opened to deter them.
This time we did not repeat our mistakes. ERIDGE maintained her slow speed while only her close range weapons raked the U-Boat’s hull from which riccochetting tracers described curious patterns in the air. As ERIDGE surged alongside, the final pattern of five charges was released. These were set shallow and detonated with a mighty crash, drenching the U-Boat under a great gush of water.
Men were now leaping into the sea so fire was checked and the whaler sent away with a boarding party with a slight hope of getting onboard to prevent her being scuttled. But the U-Boat was so obviously foundering that the whaler soon turned to the more humanitarian role of saving life. To the best of my recollection ERIDGE alone picked up the U-Boat’s entire company which, upon reaching Tobruk, was divided between ERIDGE, HURWORTH, and HERO for the passage to Alexandria.