The cruiser headed north the day after the submarine attack to join the ANZAC Squadron, which had been redesignated Task Force 44. On 17 June, "Canberra" took part in offensive patrols through the Coral Sea, and from July, she was assigned to Operation Watchtower; the opening stages of the Guadalcanal Campaign. The cruiser escorted the force to be landed at Tulagi from 5 August, and screened the force during the landings on 7 and 8 August; the cruiser encountered no initial resistance.