Countdown at Sea (1999)

A dream cruise becomes a voyage of terror - It's a dream assignment for young journalist Anna: to cover the maiden voyage of a luxury cruise ship. She's even allowed to bring her daughter Laura and husband Sven along. But Sven, an army frogman, is held back by a military operation. Only at the last minute does he manage to stow away on the vessel, where he soon discovers he's not the only unexpected guest: there's also a gang of brutal terrorists who take control of the ship and demand 25 million euros. When an attempted storming of the ship fails, Sven realizes that the terrorists can only be defeated from within - and that he's the only man for the job.