[1] He saw service during the American Revolution, serving with his father who (by this time) was a captain and commanded a number of ships during the war.

He then moved aboard HMS Juste and sailed to the West Indies with Sir Robert Calder's fleet.

[1] On Sawyer's return to Britain, he was put in charge of the payment of ships based at Plymouth, a job he held until he was promoted to rear-admiral on 2 October 1807.

[1] By early 1810, he was made second-in-command of Portsmouth dockyard and, by the end of the year, was again promoted; this time to the rank of vice-admiral.

In 1810 he was appointed to the post of commander-in-chief of the North American Station[1] – his father's old command – which he held during the War of 1812 before relinquishing it in 1813.