Not a novel novel...

I was passing the local Oxfam book shop this morning and noticed that they had a big run of Patrick O'Brien nautical novels. Including one I'd never heard of, The Truelove.

So I nipped in, and was about ten seconds from buying it when I thought to look at the plot summary... and discovered, of course, that it's a variant title for Clarissa Oakes.

Oh well, at least I noticed before I paid... But a bit disappointed anyway.

Meanwhile, has anyone read "21", the unfinished Aubrey/Maturin novel? Is it worth buying?