refraining from discharges (Queen Mary 2 has a zero-discharge policy) and reducing their carbon dioxide output every year. Cruise ships require electrical power, normally provided by diesel generators, although an increasing number of new ships are fueled by liquified natural gas (LNG). When docked, ships must run their generators continuously to power on-board facilities, unless they are capable of using onshore power, where available. Some cruise ships already support the use of shorepower, while others are being adapted to do so. Sunken vessels accidentally sunk on 4 August 1991 after suffering uncontrolled flooding, no fatalities. caught fire and sank 30 November 1994, two dead. accidentally hit a reef and capsized on 6 April 2007, two dead. accidentally sunk on 23 November 2007 after hitting an iceberg, no fatalities. sank accidentally on 13 January 2012 after hitting some rocks, 32 dead. Hableány, a river cruise ship, sank on 29 May 2019 after accidentally colliding with the river cruise ship Viking Sigyn, 27 dead. See also Cruiseferry Lido List of cruise ships List of largest cruise ships List of ocean liners River cruise References Bibliography Ward, Douglas, Berlitz Ocean Cruising and Cruise Ships, published annually Further reading External links Ship types