The Far Side of the World (Aubrey & Maturin, #10)

Captain Jack Aubrey sets sail for Cape Horn, determined to intercept an American frigate before it can wreak havoc on the British whaling trade. As always, he is accompanied by intelligence operative Stephen Maturin, and as always, Aubrey has no idea of what his companion is up to. Another impeccably written adventure, by the end of which you should be able to identify a mizzen topsail in your sleep.