If you're talking about passenger cruise ships, then it would be Royal Caribbean's Oasis and it's sister ship, Allure. They weigh in at 225,282 tons and can hold 6300 passengers!
the worlds oldest warship is The Gray Monk
Britain states that her wooden sailing ship HMS Victory is the oldest commissioned warship in the world.
uss constitution
Until her retirement in January 2009, the Kitty Hawk (CV-63) was the second ship with the oldest active status in the Navy. The USS Constitution still holds the distinction of being the oldest active Navy warship.
you dhakkan
The USS Constitution, "Old Ironsides", completed in the 1790s, is still a commissioned warship of the US Navy.
Haiku
The Norwegian Skjold Class warship is considered the fastest surface ship in the world. It has been clocked at over 60 knots.
It is the sundial.
Damascus is the oldest city in the world.
Kongo Gumi is the oldest firm in the world.
eldon
battle cruiser