This novel was discovered completed after Crichton died - it's not a bad one for him to go out on, a readable entertaining piece of historical fiction reminiscent of The Great Train Robbery. There's nothing particularly amazing about it especially since the Pirates of the Caribbean franchise has made us so familiar with piratical activity.
Crichton as a historical novelist wasn't as good as Crichton the technical speculativist but its well researched as always and the story is pretty strong - it's about an English privateer raid on a Spanish settlement which proves much harder than the team who organise it think.
Characterisation was never Crichton's strong point and there's not much here beyond archetypes - horny aristocratic women, sturdy virile yet ruthless heroes, the one black pirate, the one woman pirate, the dodgy French pirate who proves untrustworthy, the Spanish villain. He doesn't quite have the action-description skills to do justice to his story - maybe another draft could have solved this problem. And I can't recall any story I've read/seen where so many guards/henchmen were killed off - seriously it was like a hundred or something. There's an intriguingly down beat epilogue.