When his father was appointed Surgeon-General to the North American station in 1779, the 10-year-old Charles went with him aboard HMS Europe, which arrived in New York City on 25 August. On 23 December, Charles transferred to HM Sloop "Loyalist" and assisted in the capture of Charleston, South Carolina on 12 May 1780. He spent a short period aboard HMS "Renown", which was dismasted in a gale while escorting a convoy to Quebec, before returning to "Loyalist" where he was promoted to Able Seaman and then Midshipman. Bullen returned to England in July 1781 aboard HM Sloop "Halifax" along with his father and Rear Admiral Arbuthnot, who had had some differences of opinion with Admiral Rodney.