This was a British small-scale naval operation by motor launches of Admiral Sir James Somerville’s Eastern Fleet (January 1944).
At the end of 1943 the 121st Flotilla reached Chittagong in south-east India, and on 7 January 1944 HDML-1120 and HDML-1115 departed for the related 'Blast' (i), 'Brisk' and 'Bandoola'. These undertakings demanded an entry into the estuary of the Irrawaddy river, a voyage of more than 1,000 miles (1510 km) from south-eastern India through Japanese-controlled waters. The launches were unable to communicate directly with the base at Chittagong, so ML-477 anchored off Calventures island as radio relay link. Shoals made it impossible for the launches actually to enter the Irrawaddy river, but the flotilla vessels gained a number of successes before being attacked by Japanese bombers off Bassein Point.
The Japanese dropped about six bombs, but broke off when they were engaged by accurate 3-pdr gunfire from the coastal craft. Two days later ML-475, ML-438, ML-440 and ML-441 carried out the successful 'Birdline' and 'Bate'. At this time Captain J. Ryland, the Captain Coastal Forces, and his staff arrived in Chittagong, and Lieutenant P. Munro was preparing the advance base farther to the south on the Naf river.
During January 1944, the Arakan coastal forces were strengthened by the arrival of one South African and two British flotillas. The Japanese were now being very aggressive ashore and heavy air attacks were being aimed at Chittagong.
ML-477, ML-441, ML-474 and ML-476 carried out 'Harass', a gunfire bombardment of the Japanese positions on Ramree island, on 25 January and again on 2 February. Over the same period a Royal Navy officer was taken to St Martin’s island to survey the approaches to the Naf river.
Lieutenant A. J. Howard’s 56th Flotilla carried out its first operation at the beginning of February when ML-412, ML-419, ML-416 and ML-413 bombarded Minbyin. During the bombardment ML-419 was attacked by eight aircraft: one bomb struck the armour plating on the bridge, went through the deck and vessel’s side, and exploded in the sea.
A few days later Japanese aircraft attacked ML-416, which was on a secret mission to the south-west of Cox’s Bazar. The launch’s gunners responded with accurate fire, which caused one of the warplanes to disappear in a steep dive.
In order to garner intelligence and harass the Japanese an amphibious force was established as the 290th Special-Purpose Company under the command of Major T. L. F. Firbank. This force was escorted on operations by motor launches, whose crews derived a great deal of amusement from orders they heard given to the wheel and from the navigational methods of the military commanding officers of the force’s five old steamers.
On 12 February ML-413 was to have convoyed two of the 290th Special-Purpose Company’s ships carrying the 11th West African Reconnaissance Regiment and V-Force scouts in 'Screwdriver'. One of the 290th Special-Purpose Company ships did not arrive, so the raiders were embarked in ML-413. The party proceeded to a point south of Sitaparokia Rock, which was known to be held strongly by the Japanese. The raiding party was landed just before 24.00 and re-embarked just after 02.00 having been in action and obtained much useful information.
ML-439, ML-438, ML-476 and ML-440 then carried out 'Bowsprit' and 'Pickup'. At the same time ML-413 transported part of the the 290th Special-Purpose Company that landed by dinghy 2 miles (3.2 km) to the south of Donbaik. The operation was successful and the party returned to Teknaf on 15 February.
Shortly after this, the Japanese started their important 'Ha' (iv) undertaking to take the Mayu peninsula. It was estimated that the Japanese had more than 200 aircraft available, and the base at Teknaf was frequently machine gunned.
At the end of February 1944 the Arakan Coastal Forces moved to the Advance Base at Teknaf. The army now wished to pin as many Japanese as possible on the coast, so Lieutenant Commander H. M. Darbyshire, in ML-477, sailed with the 55th Flotilla augmented by two craft each from the 56th and 49th Flotillas, and carried out a gunfire bombardment of Akyab on the night of 26 February. There was opposition from 75-mm (2.95-in) guns and machine guns, but the force returned to Teknaf at dawn without suffering casualties or damage.
During operations by the 55th and 56th Flotillas to intercept Japanese sea traffic, some small craft were found to be carrying cargoes of vegetables to the garrison on Round island, and when the two flotillas returned to base they had sunk six boats and brought back 24 prisoners. The latter were interrogated by the Military Intelligence Department and among a mass of valuable information were details of routes used by Japanese supply vessels.
In order to cut these supply routes, six launches (three of the 55th Flotilla and three of the 56th Flotilla) departed on 7 March 1944. They searched Andrews Bay and Sandoway Bay without opposition, but, as information from a captured Burman indicated that a Japanese gun was mounted near the jetty, range was closed to 800 yards (730 m) for a bombardment. The Japanese position was silenced before the launches withdrew to the Naf river base.
On 11 March Forces 'A' and 'B', comprising three launches of the 56th Flotilla and three of the 55th Flotilla respectively, departed the advance base and bombarded the Japanese headquarters at Sitaparokia Rock. The Japanese shore battery opened fire, but, apart from inflicting very slight damage on ML-438, this was ineffective and soon silenced. Landing craft had by this stage reached Teknaf and, while the bombardment of Sitaparokia Rock was in progress, the first attack by elements of Brigadier W. I. Nonweiler’s 3rd Special Service Brigade had taken place some 12 miles (19 km) to the south of Maungdaw. ML-416 and ML-417 provided support off the beach-head, and were also called at short notice to assist in the evacuation of troops, who had met heavy opposition. A smoke screen laid by ML-476 greatly helped to get all back safely.
ML-412, ML-419 and ML-417 entered Gwa Bay without opposition during the following week, but located no Japanese vessels and therefore bombarded Coconut Point and the village beyond it. The three launches were heavily engaged by Japanese mortars as soon as they opened fire, but the mortars were silenced before they could inflict any damage, although ML-417 had some very near misses. On the return passage the launches were attacked by Japanese aircraft, but all the craft returned safely on 19 March.
The operations of 1943/44 ended with a bombardment down the coast by the motor launches of the 49th, 55th and 56th Flotillas, which proceeded independently and met little opposition. They were then joined by ML-477, which had been carrying out hazardous long-range secret operations, in the course of which it had suffered a number of casualties. HDML-1118, HDML-1119 and HDML-1121 remained at Teknaf for river patrols, but the rest of the Arakan Coastal Force withdrew to Indian ports for refits on 23 March 1944.