Royal Air Force
Vickers Vildebeest Mark III torpedo bombers of No. 100 Squadron RAF
Malaya Command was aware that the Japanese force would soon be reinforced by naval convoy, a suspicion confirmed on 26 January when a Lockheed Hudson sighted them 20 miles north of Endau at 0745. The RAF decided to attack the convoy with all available aircraft. However, their decision to use Vickers Vildebeests against the ships in daylight came as a shock to the pilots, who were restricted to the relative safety of night sorties since the invasion started.
A counter-attack was carried out by No. 36 Squadron RAF and No. 100 Squadron RAF, flying from airfields in Sumatra and Singapore. Twelve Vildebeests (2 from 36 Squadron), along with 9 Hudsons with a fighter escort of 8 Hawker Hurricanes and 15 Brewster Buffaloes, took off in the early afternoon of January 26. Japanese landings on Endau had been in progress for over four hours by the time the planes arrived at 1500. Men and equipment on the beach were bombed under heavy Japanese anti-aircraft fire and fighter opposition. Five Vildebeests were lost in the attack, including the commanding officer of 100 Squadron.
A second wave arrived at 1730, this time with 9 Vildebeests and 3 Fairey Albacores escorted by 12 fighters. By nightfall, 5 Vildebeests, all 3 Albacores and 1 Hurricane were lost along with their crews.Of the 72 aircrew who participated in both raids, 27 were killed, 7 were wounded and two were captured. The survivors were congratulated by Air Vice-Marshal Paul Maltby, who promised them that further daylight attacks were unnecessary
The Royal Navy received reports that an unescorted convoy was anchored at Endau. HMAS Vampire and HMS Thanet were tasked with intercepting the convoy and breaking up the landings. Thanet was under the command of Lt Cdr Bernard Davies, while Vampire was under Lt Cdr William Moran, The destroyers departed Singapore Naval Base at 1630 and headed north for Seribuat Archipelago where there had been reports of another Japanese convoy anchored there. Arriving at Seribuat at 0200 the next morning but encountering no Japanese vessels there, the destroyers headed for Endau.
Japanese naval intelligence, however, incorrectly reported them as two cruisers, and exaggerated that there were British submarines in the area. Therefore, the convoy’s naval escort of one light cruiser and six destroyers (they were not covering the landings at Endau), were recalled to intercept the ‘cruisers.’
On 20 January 1942, a Japanese convoy of 11 troopships departed Cam Ranh Bay, Indochina, to unload ground forces at Singora, of which two would proceed to Endau. The two transports, Kansai Maru and Kanbera Maru, were carrying troops of the 18th Division. Personnel from the 96th Airfield Battalion were also onboard (they were assigned with bringing the airfields of Kahang & Kluang into operation). They were escorted by the Japanese cruiser Sendai and six destroyers, Fubuki, Hatsuyuki, Shirayuki, Asagiri, Amagiri, Yugiri and the Japanese minesweeper W-1.
An invasion of Mersing via beach landings was originally planned by the Japanese, but believing that the allied defences there were formidable, they decided to land troops on Endau instead. Although ground forces captured Endau on 21 January, their strength was insufficient to break through the allied Sungei-Mersing defence. The allies defending the east coast of Johore was codenamed Eastforce, commanded by Brigadier Harold Taylor.