On 9 December 1737 Murray became second lieutenant of the ship of the line HMS "Hampton Court" which sailed for the West Indies in 1738 as the flagship of Commodore Charles Brown. As such Murray participated in "Hampton Court" in the Battle of Porto Bello on 20 November 1739; she created so much smoke from the frequent firing of her guns at a gun battery that the other ships of the fleet at one point thought she was on fire.