The Macedonian (Privateers & Gentlemen)

Captain Favian Markham, USN, is a man surrounded by secrets. Secrets that will be revealed when he is court-martialed for losing his ship. Secrets held by his mistress Caroline. The secrets of enemy spies signaling to British ships over the horizon. And the greatest secret of the War of 1812, a secret which will be revealed once Favian breaks the enemy blockade in The Macedonian, a frigate stolen from his own government . . .

This is one of the historical novels, long out of print, with which Walter Jon Williams began his career.