After the end of the Napoleonic Wars, Brace commanded the first rate HMS Impregnable at the Bombardment of Algiers in 1816, but made a serious mistake in his navigation and exposed his ship to the port's defences unnecessarily.

Polyphemus was then heavily engaged in the Expédition d'Irlande during the winter of 1796–1797, when a French invasion fleet was broken up by storms off Southern Ireland.

[1] In consequence of the capture, Brace was given command of the brig HMS Kangaroo in June 1797 and in October 1798 was heavily involved in the events surrounding the Battle of Tory Island, bringing warning to the squadron at Cork of the approaching French fleet and subsequently assisting in the capture of the frigate Loire as the French fleet broke up in the aftermath of the battle.

In December 1811, Brace moved to HMS Berwick and for the next three years operated against the French, Spanish and Italian coasts, including the capture of the cities of Genoa and Gaeta.

[1] At the end of the Napoleonic Wars, Brace remained in service and took command of the second rate HMS Impregnable under Rear-Admiral David Milne, participating in the Bombardment of Algiers in 1816.

Impregnable suffered 210 casualties in the engagement and Brace was blamed for the losses and refused any form of reward from the British government.