His next appointment came in 1777, with the command of HMS "Boyne". He sailed with her the following year to join Rear-Admiral Samuel Barrington off the West Indies, and was present at the repulse of Charles Hector, comte d'Estaing's attempt to capture St Lucia on 15 December that year. Sawyer remained in the Caribbean, and was present at the Battle of Grenada as part of Vice-Admiral John Byron's fleet on 6 July 1779. Sawyer returned to England in the autumn, and was given command of HMS "Namur" in 1780. He commanded her in the English Channel, and was present at the relief of Gibraltar in April 1781. He left the "Namur" in December, and by 1783 he was in command of the guardship HMS "Bombay Castle" at Plymouth.