For my new book 'Pirate Hunters', I follow John Chatterton and John Mattera, two world-class scuba divers, who teach themselves to think and act as pirates while searching for what would be only the second pirate ship ever found and positively identified.

There is pressure when you have a very big book like 'Shadow Divers' to follow up with something big. But you can't let that pressure determine what you do. You just look for the best stories, and when you find a great one, you tell it.

Rereading, we find a new book.

Each new book is a tremendous challenge.

Pirates almost never sailed with women. Just four or five are known to have worked as pirates during the Golden Age. Two of them - Mary Read and Anne Bonny - became famous, dressing as men and fighting alongside one of the most celebrated of all pirate captains, 'Calico' Jack Rackham.

Piracy was risky business, and injuries were commonplace; a single lost limb or gouged-out eye could end a pirate's career. To encourage pirates not to hesitate in battle - and out of a sense of fairness - many pirate crews compensated wounded crewmen in predetermined amounts.