On 9 and 10 May 1918 at Ostend, Belgium, after the crew of HMS Vindictive had been taken off, Bourke, commanding Motor Launch 276, went into the harbour to check that everybody had got away. After searching and finding no one, he withdrew, but hearing cries from the water he turned back, found an officer and two seamen clinging to an up-turned boat, and rescued them. During this time the motor launch was under very heavy fire and was hit 55 times, once by a 6-inch shell which killed two of her crew and did considerable damage. Lieutenant Bourke, however, managed to take her into the open sea, and was taken in tow. In recognition of his gallantry and devotion to duty, Bourke was gazetted the Victoria Cross on 27 August 1918.