Till last year, the ship carried thousands of troops, civilians and supplies between the east and north coasts of a nation at war.
On New Year's Eve it will carry flowing liquor and warm food on board, fireworks above, and around 400 guests gyrating to the tunes of DJs from UK and Turkey.
The ship, the Jetliner of the Sri Lankan Navy, will be the venue of a party in Colombo.
Between 2006 and 2009, the ship, under the protection of fighter aircraft, artillery guns and helicopter gunships, ferried troops and civilians between Trincomalee (east) and Jaffna (north) as the land route was closed.
"The ship was the most important target for the LTTE. The Sea Tigers attacked it several times, but we repulsed them," navy spokesperson, captain A Senarath, said.
Now a private company has hired the vessel for over a million Sri Lankan rupees (around Rs 4 lakh) for the night-long party.
"The party will start at 9pm and end at 7am. The cruise will end at 12:30am," organiser Keminda Attygalle said.
The Jetliner has been in demand since the navy decided to put it on hire.
"The ship is booked for months in advance for weddings and conferences," Senarath said.