As 1941 drew to a close it was becoming apparent that war with Japan was becoming more of a probability. To safeguard Commonwealth and Imperial interests in South East Asia, Force Z, built around Prince of Wales and Repulse, was despatched to Singapore. The recently-commissioned carrier Indomitable was earmarked for the Eastern Fleet but could not have arrived until after the battleships. To make matters worse, she grounded off Jamaica while working-up, and, despite the magnificent efforts of the US Navy Yard at Norfolk, Virginia, which fitted a prefabricated bow section in just 10 days, the ship was sufficiently delayed to be no closer than Cape Town when the two capital ships were sunk off Singora on 10 December 1941 by IJN aircraft; RAF fighter cover arrived over the stricken ships too late to be of any value.
With Singapore untenable as a fleet base, and in the absence of suitable capital ships for the formation of a balanced Eastern Fleet, Indomitable did not immediately proceed to join the fleet. She arrived at Colombo in February after calling at Aden, where she had disembarked her Fulmars and a squadron of Albacores to make room for fifty RAF Hurricanes. The fighters were flown-off in two ranges, on 27 and 28 January 1942, to Batavia (now Djakarta) in Java, but they were too late to affect the outcome of the campaign in the East Indies, and all were lost within 48 hours, mainly on the ground.
Indomitable returned to Aden to collect another fifty Hurricanes and delivered these to Ceylon, this particular consignment providing a reasonably strong fighter force for an area hitherto virtually undefended. After another round trip to Aden to collect her two squadrons, Indomitable eventually joined Admiral Sir James Somerville’s Eastern Fleet at Addu Atoll, the fleet anchorage in the Maldive Islands. After 37 months of a war which had seen heavy naval losses, other theatres had been robbed to provide the Eastern Fleet with a balanced fleet which included three carriers and five battleships, together with a number of modern cruisers. Formidable had joined the Eastern Fleet after repairing the battle damage incurred off Crete, 10 months before, and with Hermes and Indomitable the fleet possessed thirty-nine fighters and fifty-seven strike aircraft, as well as the Walruses aboard four cruisers. Ashore in Ceylon, at Ratmalana, were 803 and 806 Sqns, newly flown out from the Middle East. There were also a few Swordfish of 788 Sqn ashore, while the main air strength was provided by the RAF, although the only RAF search and strike elements were the twelve Catalinas of 205 Sqn RAF and 413 Sqn Royal Canadian Air Force, together with the fourteen Blenheims of 11 Sqn, the latter’s crews being untrained in shipping strike.
The opposition was provided by Admiral Nagumo’s First Carrier Striking Force, including Akagi, Hiryu, Soryu, Shokaku and Zuikaku with over 300 modern fighter, search and strike aircraft embarked. These ships were the veterans of Pearl Harbor and Darwin, and their primary objective was the destruction of the Eastern Fleet and its base at Colombo.
Aware of the critical shortage of fleet fighters, and in view of the known vulnerability of his strike aircraft in day operations, Somerville relied upon the handful of Catalinas to provide him with initial sighting reports to enable the Eastern Fleet’s carriers to launch a night strike, a form of attack in which the FAA was unequalled.
The enemy searched for Somerville’s ships throughout 1 and 2 April, refuelled, and then struck at Colombo on the 5th, Easter Sunday 1942. Meanwhile, the Eastern Fleet, unable to establish contact with the enemy, returned to Addu Atoll on the assumption that the Japanese had learnt of the concentration of warships and had abandoned the operation. Hermes was detached to Trincomalee for a self-refit, and the cruisers Dorsetshire and Cornwall were also detached from the main body for other tasks. On 4 April, the day before the strike on Colombo, a Catalina at last found and reported the enemy fleet, and upon receipt of the information Admiral Somerville took his carriers to sea again in an attempt to find and strike at the enemy during the night. The search failed, and the Japanese launched a strike just after dawn on 5 April, attacking Colombo. They failed in their main objective, as there were only minor warships and little merchant shipping in the harbour. Although some damage was inflicted on the port installations, this was insignificant when compared with the havoc wreaked on Darwin at the end of March by the same carrier force. The RAF Hurricanes met the strike, but only seven enemy aircraft were destroyed by all the defences, out of 127 carrier aircraft. Thirteen Hurricanes were shot down by the Zeros, together with a flight of six of 814 Sqn’s Swordfish, en route from Trincomalee to Minneriya, where they were intended to form the sole specialised landbased shipping strike force.
Towards noon on the same day enemy search aircraft sighted Dorsetshire and Cornwall as they were steaming to rejoin the fleet, and in the early afternoon the two cruisers were sunk by dive-bombers. Extensive searches by Indomitable’s Albacores resulted in the sighting of one of Nagumo’s carrier divisions just before nightfall, to the northeast of Somerville’s position. The subsequent night ASV search did not regain contact with the enemy, who had withdrawn to the southeast to replenish before the next phase of his planned operations.
Fearing that the enemy may have positioned himself between the Eastern Fleet and its base at Addu, Admiral Somerville returned thence on 8 April, after assuring himself that there were neither submarines nor heavy surface units in the vicinity.
In the meantime he had searched to the south of Ceylon, while Admiral Nagumo searched to the north of the Eastern Fleet. Abandoning any hopes of bringing the latter to battle, the Japanese replenished once more and headed northeast to strike at the naval base at Trincomalee. Fortunately a Catalina sighted the enemy fleet heading for the island and an accurate assessment of his intentions was made. Trincomalee was cleared of all shipping that could be moved, including Hermes, and when the enemy struck, just after dawn on 9 April, there were few targets left. Again the defending fighters scored few kills and suffered disproportionately heavy losses, but again the enemy had little positive success, sinking nothing larger than a floating dock. As the strike retired, Hermes was sighted, although she was not attacked for another three hours. Despite being only 65 miles from Trincomalee the RAF was unable to scramble the surviving Hurricanes in time to save the small carrier from being overwhelmed by Aichi D3As, which scored over forty hits in 10 minutes on the undefended ship. The first fighters on the scene were the naval-manned Fulmars of 277 Sqn RAF and the Fulmars of 803 Sqn. These arrived just in time to see Hermes go down, in company with two Fleet Auxiliaries and two corvettes. The Fulmars attacked the dive-bombers as they were attacking the latter group, but were too late to save the four ships.
Hermes was the only Royal Navy carrier to be lost to air attack in the course of the war. At the time of her loss she had no aircraft embarked, and even when operational she carried no fighters. Her armament and protection were in no way comparable with that of the more modern carriers, while the number of hits scored by the efficient Japanese dive-bomber force was far in excess of any sustained by any similar warship. She was lost mainly because shorebased air cover was not forthcoming in sufficient time, just four months after the loss of Prince of Wales and Repulse in broadly similar circumstances.
After the mixed success enjoyed by the Japanese they withdrew to make good their losses, mostly non-combat, and to prepare for their next major operation, the occupation of Midway Island, some 6,000 miles to the east. At the Battle of Midway on 4 and 5 June 1942 the USN carriers Enterprise, Hornet and Yorktown destroyed all four of the Japanese carriers, for the loss of the Yorktown. From this date the Japanese were never again in a position where they could afford to commit carriers to a raiding foray in the Indian Ocean, and although the Royal and Allied navies continued to maintain a reasonably strong Eastern Fleet until the end of 1942, no warship larger than a cruiser was used operationally in the Indian Ocean by the Japanese after April 1942.