SpoilerIt doesn't explain how the director could take a location as awesome and evocative as a genuine sailing ship, on the water on a perfect night, and completely fail to put any kind of excitement or atmosphere into the proceedings. And the BBC are supposed to be good at period drama.
Cliches are cliches because they get used to much, not because they don't work. In fact, see the classic episode, The Pirate Planet for how pirate clishe was done well. Albeit in a sci-fi rather than period setting.