Queen Mary 2 docked in Liverpool last weekend to celebrate a milestone Cunard's Queen Mary 2 (QM2) docked in Liverpool last weekend to celebrate the milestone of her 400th transatlantic crossing. Constructed between 2002 and 2003, she is the only ocean liner left in service. Ocean liners are a type of passenger ship whose primary purpose is to travel across seas or rivers.

Cruise ships do not fall into this category as their primary use is for pleasure voyages rather than for transportation. Liners are used to carry cargo across oceans but can also be used for cruises - which is the case with QM2. She has the capacity to carry 2,691 guests and 1,173 crew.

The ship, which is Cunard's flagship, is of staggering scale. She is 345m long and 72m high - dominating the skyline when berthed in Liverpool. On board, she possesses all the luxury and expansive facilities you would expect from Cunard , including 15 restaurants and bars, five swimming pools, a theatre, a ballroom, a casino and even the first planetarium at sea.

QM2, which carries the Royal Mail Ship (RMS) prefix as a liner, was constructed as a new generation ship and long-term replacement for Queen Elizabeth 2. QE2 was Cunard's flagship from 1969 to 2004 before being retired by the cruise line in 2008. After construction in France, QM2 was christened by Queen Elizabeth II in Southampton in January 2004.

She set sail to Florida on her maiden voyage later that month. Her first year of service saw her sail to Athens during t.