S4·E6 Dead Reckoning

When a trawler sinks off the coast of North Yorkshire, taking the lives of five people, an enquiry establishes that the boat was in disrepair. Kavanagh is on the team prosecuting the boat owner and father of one of the victims, charged with five counts of manslaughter. He must counter the owner's defence that a Royal Navy submarine surfaced near the trawler and capsized her.