In 1941 he returned to Australia and served as a lieutenant gunnery officer in ( light cruiser) at the Battle of the Coral Sea, and later () until 1944. While serving in HMAS "Australia", Peek was injured during the kamikaze attack at the Battle of Leyte Gulf—that took the lives of Captain Emile Dechaineux and thirty others—and for his efforts immediately after was made an Officer of the Order of the British Empire for his "Skill, determination and courage" during the battle. Peek was additionally decorated with the Distinguished Service Cross for "Gallantry and skill" during assault operations on the Lingayan Gulf.