The Boat That Rocked, or is it Pirate Radio?

The Trailer for the new film by the gang that brought you Four Weddings and a Funeral, Notting Hill and Love, Actually. The film is called The Boat that Rocked in the UK and Pirate Radio in the US. Why exactly? Can the Brits not handle the idea of pirates? Do boats rock in the US at all? "Search me," as the Brits would say, and if you're reading this in the States, "Go Figure"!