Jack Aubrey and Stephen Maturin, having heard the details of Napoleon's defeat at Waterloo and having collected their share of the prize from their last capture, set sail for the dual mission of charting the Chilean coast and aiding those who seek independence from Spain.

"[1] The "deeper sense of the culture of the age" that marks the series is also true of this novel, which shows the "period of deflation, both economic and emotional" for the Royal Navy and its associated businesses after the victory.

";[1] and readers can so easily enter this fictional world, because "O'Brian did the hard learning long ago and then began to write with fully justified assurance and pleasure.

Maturin receives a coded report from Dr Amos Jacob regarding the Chilean situation and takes the Ringle to England, where Sir Joseph Blaine updates him.

Fully fitted, the Surprise stops at Funchal, picking up Jacob, and then heads for Freetown, where Maturin proposes marriage to a young attractive widow named Christine Wood.

The Surprise and Ringle make sail and Aubrey elaborates a plan to drop Chilean troops at Concepción while the ships destroy the gun-emplacements at Cala Alta and then bombard the fort at Valdivia.

He decides to pre-empt action against Surprise by cutting out the Peruvian fifty-gun frigate Esmeralda at Callao in Peru to strengthen the Chilean navy.

Whilst in Sierra Leone, Christine Wood shows Stephen Maturin a prodigious amount of wildlife, including: Sailing in the Atlantic out of Shelmerston, a pod of seven right whales, Eubalaena glacialis, swam past the Surprise, one surfacing to clear the blow hole, evoking a former whaler's cry, not a proper Royal Navy communication (thar she blows).

Shelmerston, the home port of HMHV Surprise since she was bought out of the service by Maturin is fictional, but based on a real place on the western coast of England, Appledore near the River Torridge in Devon.

For sailing vessels going east to west, the Strait is more challenging, due to its narrowness and prevailing westerly winds, than rounding Cape Horn, which is further south.

[3] Publishers Weekly thinks readers may find this novel the best of the series, with Maturin's love letters "functioning as a chorus to the action."

[4] They noted also the introduction of "Horatio Hanson, bastard son of a nobleman, who comes on board as a midshipman, a dashing young foil for the ship's elders.

""[4] Writing in The New York Times, Amanda Foreman remarks that Blue at the Mizzen is "a shining jewel" and "an intricate, multifaceted work -- one of those rare novels that actually bear up under close scrutiny."

"[1] John Casey, writing in The Washington Post wrote that O'Brian covered the "year after Waterloo, so it necessarily deals with a period of deflation, both economic and emotional, for the Royal Navy and its ancillary population of shipwrights, chandlers and seamen on the beach."

"[2] Then the two main characters have their mission to aid Chile, and "Of course Jack and Stephen must sail there, and readers are treated to O'Brian's talent for life on board, incidents and accidents".

[2] The narrative is primarily from Aubrey and Maturin, but "occasional glimpses from other perspectives that both give a capsule story -- in this case a sense of a calculated marriage -- and also provide contrast: Jack, for all his faults, is not "capable of a shabby thing.

Casey offered that readers can so easily enter this fictional world, because "O'Brian did the hard learning long ago and then began to write with fully justified assurance and pleasure.

The political intrigue in revolutionary Chile is right up Stephen's alley, while Jack's fighting skills also are called into play, culminating in a satisfying naval action that, as always, brims with historically accurate detail.

As the Frenchman said: 'Le style est l'homme même', and just as Aubrey is no longer the exuberant young commander of the early novels, so O'Brian's narrative has matured with him.

"[5] English language editions listed for UK and USA markets[8] Publishers Weekly noted that over three million copies of the books in the Aubrey-Maturin series have been sold, by November 1999.

[4] Kirkus Reviews wrote that "O'Brian announced long ago that he hoped to write 20 volumes in his series centering on the British Navy during the Napoleonic Wars and featuring Jack Aubrey and Stephen Maturin.