This is book 2 of the "Richard Delancey" series.

This note contains spoilers for the book.

This is the one I heard of first, and in fact the one that was published first (1973). Making it contemporary with the early O'Brian (1969; 1973 was H.M.S. Surprise).

Once again Delancey ends up in temporary command in a strange situation. He's on the beach due to a court-martial from his involvement in getting rid of an incompetent captain, and gets a temporary command on a secret mission.

But before that, he works to help the most hated institution on the sea-coast—the revenue cutters.