Born the second son of William Rowley and his wife, Elizabeth Rowley (née Baldwin), Rowley joined the Royal Navy as a volunteer in 1704. He was assigned to the third-rate HMS "Orford", commanded by Captain John Norris, and saw action in the Mediterranean during the War of the Spanish Succession. Having passed his exams for lieutenant on 15 September 1708, he transferred to the third-rate HMS "Somerset" in December 1708. After carrying out diplomatic duties for King George I in Paris in early 1716, he was promoted to captain on 26 June 1716 and given command of HMS "Bideford" at Gibraltar and was involved in naval action against pirates. He transferred to the command of the sixth-rate HMS "Lively" in the Irish Sea in September 1719 and then went on half-pay in June 1728.