During the Jacobite rising Brett saw action on 9 July 1745, when as captain of the fourth-rate he exchanged fire with the French ships Elizabeth and the Du Teillay. The Du Teillay at the time was carrying Charles Edward Stuart to Scotland with supplies and funds to support his cause. The Lion suffered severe damage and had to give up the pursuit and Charles eventually landed at Eriskay. He transferred to the command of the third-rate in 1747 and commanded her at the First Battle of Cape Finisterre in May 1747 during the War of the Austrian Succession.