First action of any kind happened on 10 Dec 1941 when Japanese bombers sank HMS PRINCE OF WALES, (battleship), and HMS REPULSE, (battle-cruiser), in the South China Sea. HMAS VAMPIRE, (destroyer), picked up survivors. One of those lost in the sinking of HMS REPULSE was MIDN R. I. Davies, RAN, who commanded an Oerlikon gun on the port side of the battle-cruiser. The Naval Review wrote: An Australian midshipman was still firing his Oerlikon gun at an aircraft; several enemy aircraft were brought down by Midshipman Davies after the order to abandon ship had been given.
First engagement with the Japanese Navy was 21 Jan 1942, when off Darwin, NT, HMA Ships DELORAINE, KATOOMBA, and LITHGOW, (corvettes), with the USS EDSALL, (destroyer), took part in depth-charge attacks which destroyed the Japanese submarine I124, the first warship of the Japanese navy to fall victim to the RAN in WWII.
Then on 27 Jan 1942, HMAS VAMPIRE and HMS THANET, (destroyers) launched a night attack on a superior Japanese force landing troops at Endau, Malaya. The destroyers penetrated the enemy line and engaged vessels on both quarters at point-blank range. HMS THANET was lost in the engagement, VAMPIRE escaped reaching Singapore naval base some hours later.