Royal Caribbean International on Monday ordered the world’s largest and most expensive cruise ship, above, a $1.24 billion vessel big enough for up to 6,400 passengers.

The ship, dubbed Project Genesis, is scheduled for delivery to the second-largest cruise operator in 2009 by Oslo, Norway-based shipbuilder Aker Yards. The ship is set to weigh about 100,000 tons; a Nimitz-class aircraft carrier comes in at about 97,000 tons.

Aker said its contract price of about $1 billion would be “the most valuable ship ever ordered in the history of commercial shipbuilding.”