"The Genesis is a pretty big ship you know... Don't write your old man off, just yet."- Harry Helmsley
The Genesis was a cruise ship that was built on April 4, 2008, that could carry 6,212 people, 6000 passengers, and 212 crew members. The ship sailed from San Francisco, California to Tokyo, Japan.
Harry Helmsley and Tony Delgatto performed on the ship. The ship was capsized when a mega-tsunami hit it, presumably killing everyone onboard. Other ships were hit by mega-tsunamis as well.
In an alternate ending of the film, the Genesis was shipwrecked on a small island somewhere near Southern Africa with 3 survivors, Harry, Tony, and the captain of the ship but this doesn't mean that there were only 3 survivors. It's unknown if the ship got scrapped or repaired after the disaster.