On 12 May 1746, he was promoted to be captain of , then employed on the coast of Scotland; in December 1748, he was appointed to , and in March 1749, to .
War had not then been declared, but hostilities had been going on for several months, as Shuldham very well knew, and the story that he mistook the enemy's ships of war for merchantmen would be but little to his credit if there was any reason to suppose it true.