World's Biggest Vessel Ever To Sail The Seas Is Launched From Korean Dockyard, But What Were The Biggest To Sail Before it?

It is 488 meters (1,600 feet) long and when it has a full load it will weigh more than 600,000 tonnes and will displace as much water as six aircraft carriers. The Prelude, Royal Dutch Shell plc's (NYSE:RDS) new $12 billion vessel, is, according to analysts, supposed to be a “game changer” in the oil and gas industry.

It was launched in South Korea on Wednesday and will operate as a Floating Liquefied Natural Gas (FLNG) platform off the coast of Western Australia starting in 2017.

Nearly 100 meters high and longer than the Empire State Building, the Prelude immediately displaces Ap Moeller-Maersk A/S-B's (Copenhagen:Maerskab) Emma Maersk as the largest vessel ever to go to sea.

Its job will be to spend the next 25 years at sea sucking gas from the bowels of the earth, process it all onboard and then funnel it to ships to take ashore. Every year it will pump 3.9 million tons of gas.

The ship will be connected to the sea floor by mooring lines that run through a near-100 meter turret, strong enough to withstand a category 5 storm.

While the Prelude is now the biggest seagoing vessel in the world, an even bigger ship is in the making, says Shell. But large vessels have always been a mainstay in the oil industry and even as long ago as the 1970s ships were exceeding 1500 feet in length.

Here are the biggest ships ever to have sailed the seven seas:

The Seawise Giant 458.48 meters (1,504 feet). 1979-2009 (broken up)

Pierre Guillaumat 414.23 meters (1,359 feet). 1977-1983 (broken up)

Batillus 414.22 meters (1,358 feet). 1976-1985 (broken up)

Bellamya 414.22 meters (1,358 feet). 1976-1986 (broken up)

Prairial 414.22 meters (1,358 feet). 1979-2003 (broken up)

Esso Atlantic 406.57 meters (1,334 feet). 1977-2002 (broken up)

Esso pacific 406.57 meters (1,334 feet). 1977-2002 (broken up)

Maersk triple E class 399 meters (1,309 feet) 2013 (in service) – 20 ships

Maersk E class 397.71 meters (1,305 feet) 2006 (in service) – 8 ships

Explorer class 396 meters (1,299 feet)2012 (in service) – 3 ships

Nai Superba 381.92 meters (1,253 feet) 1978-2001 (broken up)

Nai Genova 381.92 meters (1,253 feet) 1978-2000 (broken up)

Berge Emporer 381.82 meters (1,253 feet) 1975-1986 (broken up)

Berge Empress 381.82 meters (1,253 feet) 1976-2004 (broken up)