Within one week of the Japanese's occupation of Subic Bay and Grande Island, American PT boats at Cavite were ordered to attack a Japanese ship, which was anchored at Subic Bay, that was shelling American positions. PT-31 and PT-34 entered the bay separately. PT-31 suffered engine trouble and ran aground on a reef. She was abandoned and destroyed. PT-34 entered undetected and sunk a transport that was off-loading supplies. She then came under heavy fire but managed to escape undamaged. PT-32 was then ordered into Subic Bay and attacked and hit a light cruiser on 1 February. On 17 February, PT-34 made a final but unsuccessful attack at Subic Bay after which all PT boats were ordered to leave the Philippines.
