In the summer of 1945 the Allied staffs in South-East Asia were planning Operation Zipper — the liberation of Singapore and Malaya. Although the war in Europe had ended in May, Japan had not surrendered, and her forces still held the island and peninsula occupied in 1942. For security reasons the planners were denied any hint of the imminent explosion of the first atomic bomb over Hiroshima. Hence, they were preparing an assault landing in northwest Malaya and the elimination of any Japanese naval units which might try to intercept it.

The Japanese cruisers Takao and Mikyo were sighted at anchor in the Straits of Johore between Singapore and the mainland. The depot ship of the 14th Submarine Flotilla, HMS Bonaventure with six XE-craft (four-man midget submarines) in her hold, was given orders to launch XE-craft attacks to sink or disable them.

XE3, captained by Lieutenant Ian Fraser, DSC, RNR, with Leading Seaman James Magennis as crew and frogman, was assigned to attack the Takao by attaching limpet mines to her hull. Four days out from Bonaventure’s base off Labuan island, XE3 slipped her tow from the submarine Stygian and began an entry to the Singapore Channel from the east shortly before midnight on July 30. Fraser faced 40 miles of difficult passage to his objective through minefields, a buoyed anti-submarine boom and Japanese hydrophone listening posts and surface patrols.

Contrary to intelligence reports the navigation buoys marked on his charts were unlit, so Fraser spent two hours sitting astride the mini-submarine’s outer casing scanning his course ahead with binoculars. By 02.00 hours on the morning of the 31st, XE3 had passed the known hydrophone posts then, so as to avoid detection by any others, he decided to leave the safe channel and pass through a known minefield. A slow and stealthy advance on the surface was interrupted at 04.30 hours when he had to crash dive to avoid a Japanese tanker with armed escort vessels.

Finding to his surprise that the gate to the anti-submarine boom was open, Fraser took XE3 through and sighted the Takao at 12.50 hours. He began his final approach at periscope depth an hour later but was again forced to dive when an enemy motor launch appeared. Continuing the advance blind led to the nose of XE3 striking Takao’s hull with a loud clang. Fraser cautiously withdrew after noting that the cruiser was almost aground both fore and aft.

Thankful that the collision had seemingly gone undetected, Fraser returned to the attack and after 40 minutes of careful manoeuvre he placed XE3 under the cruiser’s midships section. The next move lay with Leading Seaman Magennis. Clad in his frogman’s suit his task was to exit through the submarine’s “wet and dry” compartment, unhitch the limpet mines and attach them to the cruiser’s hull. Two additional charges, attached to XE3’s port and starboard sides, would be released from inside once the limpets had been placed.

Magennis unlocked the diver’s hatch only to find it was too close to the cruiser’s hull to open fully. Realising that any delay would trap the submarine beneath the Takao as the tide fell, he inhaled deeply, pulled off his breathing apparatus to allow him to squeeze through the gap and replaced it once outside. Half an hour later he had attached the mines 50 feet apart on Takao's hull and squeezed back into XE3 using the same technique he had used for getting out.

Fraser operated the mechanism to release the two side charges in preparation for withdrawal, but only the port charge fell away. Worse still, the Takao began to settle as the tide fell and her keel was soon pressing down on XE3. For 50 minutes Fraser used every trick he knew to free his craft, and at last broke away to starboard in an upheaval of water.

The starboard charge was still attached, however, and, as Magennis appeared exhausted, Fraser prepared to go out to release it manually. But Magennis insisted on carrying out this responsibility. After exiting from the hatch wearing his breathing apparatus, he released the starboard charge with a heavy spanner.

Fraser made course for safety back along the one he had followed in the early hours of the morning, but daylight held him to a slow speed at periscope depth. Once well clear of the Singapore Channel, XE3 made a successful rendezvous with her towing submarine, Stygian. The limpet mines and side charges exploded at 21.30 hours on July 31, ripping a 60ft-long hole in the Takao’s hull, leaving her immobilised and stranded.

Fraser and Magennis returned to Bonaventure off Labuan on August 4. Two days later the first atomic bomb was detonated over Hiroshima, beginning the sequence of events which were to end the Pacific war. Consequently Singapore and Malaya were retaken without the need for an assault landing.

Such were their personalities, Fraser and Magennis were able to see the ironic side of this development. Both men were awarded the Victoria Cross, which they received from King George VI at Buckingham Palace on December 11, 1945.

Ian Edward Fraser was born in Ealing, London, in 1920, the elder son of Sydney Fraser, a marine engineer. He was educated at the Royal Grammar School, High Wycombe, and the training ship HMS Conway, from where he entered the Merchant Navy in 1937.

He joined the Royal Navy on the outbreak of war and saw action in destroyers, mainly in the Atlantic. He volunteered for the submarine service in 1942 and was awarded the DSC after a year’s intensive operations with the submarine Sahib in 1943. His involvement with midget submarines came about through his response to a signal from Flag Officer Submarines calling for volunteers for “special and hazardous service with submarines” in March 1944.

Fraser remained on the Royal Navy Reserve list until 1965, when he retired with the rank of lieutenant-commander. Putting his wartime experience to commercial use, he founded Universal Divers — a civil engineering underwater contracting company — in 1947. This proved very successful, and he turned the company over to his younger brother, Brian, in 1965.

That year he started up, with others, North Sea Diving Services, tailored to meet the requirements of the offshore oil industry. He was managing director until the company was acquired by Blue Star Line in 1975. He served on the board of Star Offshore Services until his retirement in 1982.

Fraser was an enterprising and intensely social man. Small in stature and known to many of his friends simply as “Titch”, he was an engaging raconteur. In 1957 he published Frogman VC, which dealt not only with his wartime exploits but also his struggle to establish himself in the commercially competitive postwar world.

He was appointed a justice of the peace for Wallasey, Merseyside, in 1957 and elected a Younger Brother of Trinity House in 1980.

He married in 1943 Melba Estelle Hughes, who survives him with four sons and one daughter. A daughter died recently. Magennis died in 1986.

Lieutenant-Commander Ian Fraser, VC, DSC, RD and Bar, wartime submariner, was born on December 18, 1920. He died on September 1, 2008, aged 87