In Southampton in 1916, HMHS Britannic, a sister ship of the Titanic, has been refitted as a hospital ship for Allied soldiers fighting in the Gallipoli Campaign. Among the nurses who are to serve aboard her is Lady Lewis, who is being delivered to Greece via Naples, where her husband has become Ambassador for Great Britain. Traveling with her is Vera Campbell, an operative of British Intelligence posing as Lady Lewis' governess. She is unnerved by the voyage, having survived the Titanic's sinking four years earlier, losing her husband to the sinking. She reports her mission to Captain Bartlett, who is dubious that a woman can do such a job.

A German spy has boarded the Britannic posing as her chaplain, Chaplain Reynolds, and soon discovers that the ship is secretly carrying a large amount of small arms and munitions bound for Cairo. Under the articles of war, Reynolds considers his actions against Britannic to be legal and initiates a series of sabotage attempts to either take over or sink her, including inciting the Irish stokers, all members of the Irish Republican Brotherhood, to mutiny.

Each sabotage attempt is foiled by Campbell - with the eventual co-operation of the Britannic's crew. Unaware that she is responsible, Reynolds finds himself growing attracted to her whilst the voyage continues after making a stop at Naples, Italy. They fall in love and she has sex with him before discovering his true identity. Campbell confronts him in the engine room where Reynolds reveals his real name, Ernst Tilbach, and then he tells her he is going to sink the ship.

Ernst blows a hole in the Britannic's port side bow. The ship tries sailing for Kea island seven miles away, but the beaching operation causes her to sink even faster. Campbell discovers that William, one of Lady Lewis's children, has disappeared. Ernst helps her and they get William to a lifeboat before it is lowered. Another explosion causes Ernst to be trapped in a flooding room. Campbell helps him escape and they make their way through the ship, swimming through flooded rooms, vents, grates, and corridors, eventually making it outside by swimming through a porthole and climbing aboard an empty lifeboat that has been lowered into the water, but is still attached by its ropes to the davits.

Campbell and Ernst notice a lifeboat filled with people getting pulled into the still spinning propellers. They watch in horror as the boat and its occupants are smashed to pieces by the spinning blades. Ernst ties Campbell to a line thrown to them from a nearby lifeboat. Despite her protests that they both can be pulled to safety, he throws her into the sea after kissing her. Soon after, the lifeboat's ropes break and it also begins to get sucked into the propellers. Ernst commits suicide, staying aboard the lifeboat as it is smashed by the blades. A few moments later, the Britannic rolls over, causing her funnels and deck machinery to tumble into the sea as she sinks. A British battleship, HMS Victoria, arrives to rescue the survivors. Reflecting on her experience, Campbell quotes the poem "Roll on, Thou..." from Childe Harold's Pilgrimage by Lord Byron.

David Kronke, Los Angeles Daily News, was somewhat complementary about the films humour and short running length, when compared to 1997's Titanic, but felt that the movie "bl[ew] it in the last half hour", due to badly executed plot contrivance and the climax being to similar to that of Cameron's. He was also critical of Jacqueline Bisset's acting.^[5] Ray Richmond, writing in Variety, thought that the movie was an attempt to cash in on the popularity of the 1997 movie, but without an equivalent budget or pathos and felt that although it did "everything in its power to emulate [...] 'Titanic'" it came "far closer to outright satire." He concluded that "Authenticity proves the greatest casualty."^[6]

• List of American films of 2000

• Britannic at IMDb  
• Britannic at AllMovie
• Britannic at Yahoo! Movies