Inglis passed his lieutenant's examination on 6 February 1755, having by now spent ten years serving in the navy. He was appointed to the 74-gun , at that time under the command of Captain Abraham North, and by April 1756 had been transferred to , also of 74 guns, under Captain Wittewronge Taylor. Inglis followed Taylor to his next two commands, the 90-gun HMS "Marlborough", and then on 3 June 1757, the 84-gun HMS "Royal William". He was then promoted to commander and received his first independent command on 17 June 1757, that of the 14-gun sloop . Inglis was initially assigned to support Hawke's September 1757 Rochefort expedition, which ultimately failed to take the town. His next appointment was to the newly completed bomb vessel in June 1759, which was assigned to support the attack on Le Havre the following month, conducted by Inglis's old commander, George Brydges Rodney. The expedition succeeded in its aim of destroying a large number of flat-bottomed boats which had been assembled in the port, thus frustrating a planned invasion attempt. "Carcass" is next recorded as having sailed to the Mediterranean in May 1759, though she was back in England by the following year, being paid off at Sheerness in September 1760.