Historians say the ship, believed to date to the 1700s, was obsolete by the time it was used around 1810 to extend the shores of lower Manhattan.
Archaeologist Molly McDonald, who first spotted two pieces of curved timber – part of the frame of the ship – peeking out of the mud on Tuesday, said: “A ship is the summit of what you might find under the World Trade Center. It’s exciting.”
By yesterday, she and three colleagues had dug up the hull from the pit where a section of the new trade centre is being built.
Dwarfed by surrounding skyscrapers, people sank in the mud as they walked and grasped pieces of the historic wood for support – touching the centuries-old ship that might once have sailed the Caribbean.
McDonald and fellow archaeologist Michael Pappalardo work for a New York environmental consulting firm hired to document artefacts discovered at the site.
The vessel’s age will be estimated after the two pieces that first popped up are tested in a laboratory through dendrochronology – the science of using tree rings to determine dates and chronological order.
A 100lb iron anchor was found a few yards from the hull, possibly from the old vessel.
The ship probably got there because of the effort to extend lower Manhattan into the Hudson River in the 1700s and 1800s using landfill.
It usually involved logs joined together but a derelict ship was occasionally used.
The ship discovered this week was weighted down and sunk to the bottom of the river, as support for new city piers, in a part of Manhattan tied to global commerce and trade.
A similar find emerged a short distance away in 1982, when archaeologists found an 18th century cargo ship on Water Street.
The remains of the latest discovery will be removed, but the timber is so delicate it is unclear how much of it will remain intact.
The surrounding water acted as a preserver for the wood for centuries, but the remains began to deteriorate immediately on contact with oxygen.
Yesterday, archaeologists were quickly sketching, measuring and photographing the ship’s remains to help them analyse the find later.
A memorial to victims of the September 11, 2001, attacks, a multibillion dollar transit hub and a second office tower are under construction.