The RMS Queen Mary is the famous ocean liner that sailed the North Atlantic Ocean from 1936 to 1967 for Cunard Line (then Cunard White Star Line).

By John Brown and Company, Clydebank, Scotland, she was designed to be the first of Cunard's planned two-ship weekly express service from Southampton to Cherbourg to New York, in answer to the mainland European superliners of the late twenties and early thirties. Queen Mary and her slightly larger and younger running mate RMS Queen Elizabeth commenced this two-ship service after their release from World War II troop transport duties and continued it for two decades until Queen Mary's retirement in 1967. The ship is listed on the National Register of Historic Places, and is permanently berthed in Long Beach, California serving as a museum ship and hotel. The Queen Mary celebrated the 70th anniversary of her launch in both Clydebank with Clydebank Restoration Trust and in Long Beach during 2004, and the 70th anniversary of her maiden voyage in 2006.

On 2 October 1942, Queen Mary accidentally sank one of her escorts, slicing through the light cruiser HMS Curacoa (D41), with the loss of 338 lives. Due to the constant danger of being attacked by U-Boats, the Queen Mary could not stop, or even slow down, to rescue survivors.

In December 1942, the Queen Mary was carrying exactly 16,082 American troops from New York to Great Britain. While 700 miles from Scotland during a gale, she was suddenly hit broadside by a rogue wave that may have reached a height of 28 metres (92 ft). In his book, The Age of Cunard, author Daniel Allen Butler mentions that the immense wall of water damaged lifeboats on the boat deck and broke windows on the bridge �?90 feet above the waterline. The huge wave caused a list that briefly reached an astounding 52 degrees before the ship slowly righted itself. He reported that investigations later estimated that three more degrees of list (about 6 inches in the wrong direction) would have made the vessel capsize. He also said that seasoned hands on the ship felt it would indeed roll over. The occurrence was kept secret at the time. An account of this crossing can be found in Walter Ford Carter's book, No Greater Sacrifice, No Greater Love. Carter's father, Dr. Norval Carter, part of the 110th Station Hospital on board at the time, wrote that at one point the Queen Mary "damned near capsized... One moment the top deck was at its usual height and then, swoom! Down, over, and forward she would pitch." The incident inspired Paul Gallico to write his story, The Poseidon Adventure, which was later made into a film by the same name, using the Queen Mary as a stand-in for the SS Poseidon.

After the war, Queen Mary and Queen Elizabeth dominated the transatlantic passenger trade through the latter half of the 1940's and well into the 1950's. But in 1958, the first transatlantic flight by a jet began a completely new era of competition for the Cunard Queens. After many voyages, winters especially, Queen Mary sailed into harbor with more crew than passengers. By 1965, the entire Cunard fleet was leaving a trail of red ink. Hoping to continue financing their still under construction Queen Elizabeth 2, Cunard mortgaged Queen Mary and the rest of the fleet. Finally, under a combination of age, lack of public interest, inefficiency in a new market, and the damaging after-effects of the national seamen's strike, Cunard announced that Queen Mary would be sold. Many offers were submitted, but it was Long Beach, California who beat the Japanese scrap merchants. And so, Queen Mary was retired from service in 1967, while her running mate Queen Elizabeth was withdrawn in 1968. The RMS Queen Elizabeth 2 took over the transatlantic route in 1969, and in turn was joined in 2004 by RMS Queen Mary 2.

After her retirement in 1967, she steamed to Long Beach, California on the west coast of the United States, where she is now permanently moored as a tourist attraction. From 1980 to 1993, the Queen Mary was accompanied by Howard Hughes' Spruce Goose, which was located in a large dome nearby (the dome is used by Carnival Cruise Lines as a ship terminal as well as a soundstage).

It had been decided to clear almost every area of the ship below C deck (called R deck after 1950) to make way for the museum. This would take the new museum space to 400,000 square feet. It would mean the removal of all the ship's boiler rooms, the forward engine room, both turbo-generator rooms, and the water softening plant. Only the aft-engine room and "shaft-alley", right at the stern of the ship, would be spared from the cutter's torch. Remaining space would be turned over to storage or office space. One of the first problems that arose during the conversion from ocean liner to tourist attraction was a dispute between land-based and maritime unions over who was going to convert the ship into a floating hotel. The United States Coast Guard had final say though, and deemed the Queen Mary a building, since most of her propellers had been removed and her machinery gutted.

With all of the lower decks nearly gutted from R-deck and down, it was up to Diner's Club, the initial lessee of the ship, to turn the rest of the former ocean liner into a hotel. But Diner's Club Queen Mary dissolved and vacated the ship in 1970 after their parent company, Diner's Club International was sold and a change in corporate direction was mandated. This happened in the middle of the conversion process. Specialty Restaurants a local Los Angeles based company that focused on theme based restaurants would take over as master lessee the following year.

A post-war feature of the ship, the first-class cinema, was removed for kitchen space for the new Promenade deck dining venues. The first-class lounge and smoking room were reconfigured and converted into banquet space, while the second-class smoking room would be subdivided into a wedding chapel and office space. On Sun Deck, the elegant Verandah Grill would be gutted and converted into a fast-food eatery, while a new upscale dining venue would be created directly above it on Sports Deck in space once used for crew quarters. The second-class lounges would be expanded to the sides of the ship and used for banqueting. On R-deck, the first-class restaurant was reconfigured and subdivided into two banquet venues, the Royal Salon and the Windsor Room. The second-class restaurant would be subdivided into kitchen storage and a crew mess hall, while the third-class dining room would initially be used as storage and crew space. Also on R-deck, the first-class Turkish bath complex, the 1930s equivalent to a spa, would also be removed. The second-class pool would be removed and its space initially used for office space, while the first-class swimming pool would be used for hotel guests. Combined with modern safety codes, and the structural soundness of the area directly below, the swimming pool is no longer in use. There is not a single crew cabin left intact aboard the ship today. She now serves as a hotel, museum, tourist attraction, and for-rent site for events, but her financial results have been mixed.

Ghosts have been reported on board only after she reached California. Many areas are rumored to be haunted. Reports of hearing little children crying in the nursery room, actually used as the third-class playroom, and a mysterious splash noise in the drained first-class swimming pool are cited. In 1966, 18-year-old fireman John Pedder was crushed by a watertight door in the engine room during a drill, and his ghost is said to haunt the ship. This aspect of the Queen Mary has been carefully used as part of marketing the ship in recent years, much to the dismay of her maritime history supporters.

The Queen Mary operates daily tours with theatrics applied for dramatic effect. Guests may also pay for private paranormal investigations, and are encouraged to document their paranormal experiences, if any.[8] The ship also maintains a haunted maze and expands to multiple mazes during Halloween called Queen Mary's Shipwreck.

The Queen Mary has been the subject of numerous professional paranormal investigations by printed publications like Beyond Investigation Magazine [4], nationally televised shows like Ghost Hunters, Most Haunted, Dead Famous and radio's Coast to Coast AM. The UK paranormal television program, Most Haunted, investigated the ship in a special two-part episode.

Notably, paranormal-themed show The X-Files filmed a 1998 episode on the Queen Mary. The episode concerned a time warp in the Bermuda Triangle, and the ship stood in for a WWII-era boat.