RMS Queen Mary 2 (also referred to as the QM2) is a British transatlantic ocean liner. She has served as the flagship of Cunard Line since succeeding Queen Elizabeth 2 in 2004. As of 2022, Queen Mary 2 is the only ocean liner (as opposed to a cruise ship) still in service. Queen Mary 2's facilities include fifteen restaurants and bars, five swimming pools, a casino, a ballroom, a theatre, and the first planetarium at sea.