Fiction 2004, October HarperCollins; Hardback 2004, October W. W. Norton; Hardback as 21: The Final Unfinished Voyage of Jack Aubrey 2004 Recorded Books audio cassette as 21: The Final Unfinished Voyage of Jack Aubrey / 978-1-4193-1278-6 (USA edition) 2004, January Recorded Books audio CD as 21: The Final Unfinished Voyage of Jack Aubrey / 978-1-4193-1280-9 (USA edition) 2004, October Recorded Books audio CD as 21: The Final Unfinished Voyage of Jack Aubrey / 978-1-4193-0893-2 (USA edition) 2005, April HarperCollins paperback / 978-0-00-719470-4 (UK edition) 2008, June Harper Perennial paperback / 978-0-00-727564-9 (UK edition) 2008, September Blackstone Audiobooks audio MP3/CD as 21: The Final Unfinished Voyage of Jack Aubrey / 978-1-4332-2961-9 (USA edition) 2008 September Blackstone Audiobooks Audio CD as 21: The Final Unfinished Voyage of Jack Aubrey / 978-1-4332-2958-9 (USA edition) 2008 September Blackstone Audiobooks Audio cassette as 21: The Final Unfinished Voyage of Jack Aubrey / 978-1-4332-2957-2 (USA edition) 2010, April Harper paperback / 978-0-00-735843-4 (UK edition) 2010, April Harper Collins Audio CD / 978-0-00-735871-7 (UK edition) followed by Abridged version in May 2010 2010, September W. W. Norton paperback as 21: The Final Unfinished Voyage of Jack Aubrey / 978-0-393-33933-8 (USA edition) 2010, September W. W. Norton e-book as 21: The Final Unfinished Voyage of Jack Aubrey (USA edition) 2011, December Harper e-book (UK and Canada edition) 2012, June Blackstone Audio Audio CD as 21: The Final Unfinished Voyage of Jack Aubrey / 978-1-4332-2960-2 (USA edition) In the Afterword, Richard Snow noted that 5 million copies of the books in the series had been sold to date. In its review of 21, Publishers Weekly says that over 6 million copies have been sold. This represents an additional 3 million sales since Publishers Weekly reported sales as of 1999 in their review of Blue at the Mizzen On the dust jacket of 21, the back includes an appreciation of O'Brian from Geoff Hunt, who drew covers for the 20 completed books of the series as well as for 21, beneath a monochrome drawing of a sailing ship. References 2004 British novels Aubrey–Maturin series Unfinished novels HarperCollins books