Why Haven't We Found Christopher Columbus's Ships?

This year marks the 525th anniversary of Christopher Columbus's first Transatlantic expedition, a voyage that the Italian explorer expected would take him to Asia. Instead, his crew sighted land in the Caribbean on October 12, 1492, setting in motion a series of events that would lead to the European colonization of the New World.

While generations of school children have sung of the adventures of the "Niña, the Pinta, and the Santa Maria too," the remains of Columbus' history-making First Fleet—as well as those of his subsequent three expeditions—remain undiscovered, despite decades of dedicated searching by archaeologists and shipwreck hunters alike.

Here are some of the reasons why finding the remains of the First Fleet is so difficult:

The conditions are lousy for ship preservation.

The warm waters of the Caribbean are paradise for teredo worms, which are actually mollusks with a voracious appetite for wood. Also known as shipworms and "termites of the sea," these creatures can devour an exposed wooden wreck within a decade and are the arch-nemesis of underwater archaeologists working in the region.

Any wooden vessel that resisted the predations of shipworms would also have to survive five centuries of tropical storms and hurricanes in shallow waters, observes Donald Keith, an archaeologist who has searched for Gallega, a ship from Columbus's Fourth Fleet which disappeared in 1503. "Ships lost in cold, dark, deep water have a much better chance of staying intact and maintaining their 'time capsule' value."

The landscape has radically changed since Columbus's time.

Centuries of tropical storms, changes in land use, and deforestation have significantly altered the coastlines Columbus once navigated. Greg Cook, an archaeologist who has searched for the remains of ships from Columbus's Fourth Fleet in St. Anne's Bay, Jamaica, describes coring though 20 feet of sediment to find evidence of the historic landscape. "That bay has changed so much," he observes.

Even then, what remains would be hard to find.

Archaeologists use side-scan sonar as a primary tool to find shipwrecks on the sea bottom, but if a wreck is buried under feet of sediment, sonar can be "simply blind" to it, says Cook. Another important tool, the magnetometer, detects metallic remains underwater, but since ships of this period used little metal in their construction, they can "hide very well" in a search, he adds.

"It's a search veritably for three needles in a haystack," observes James Delgado, vice-president at Search Inc. and former director of maritime heritage for NOAA.

We only really know the fate of one of the three ships.

"The only vessel lost out of the First Fleet was Santa Maria," notes Keith. "No one has yet been able to determine convincingly what happened to Pinta and Niña after their return to Europe," he adds. Cook agrees, "Since we don't know the whereabouts of the Niña and the Pinta, the Santa Maria would be the best to look for."

A 2014 claim that the Santa Maria has been discovered was roundly debunked by UNESCO.

Columbus's crew practiced recycling.

According to Columbus's logbook, the Santa Maria foundered on a reef off Cap Haïtien, Haiti, on Christmas Eve, 1492. Its hull was dismantled and used to construct the fortified village of La Navidad, which also has yet to be discovered. "Think of it as a spacecraft that's stranded on the edge of the universe," says Delgado. "[The sailors] need to rely on the remains of the craft to survive. We need to appreciate the level of recycling that took place at these sites."

So should we keep looking?

Absolutely, say researchers, but not necessarily because the Niña, the Pinta, and the Santa Maria are considered among the holy grails of ship archaeology. "Searching for a piece of a vessel [from the First Fleet] feels a little like trying to find a piece of the True Cross," says Delgado, who believes that the most important archaeological discoveries surrounding Columbus's voyage will illuminate the earliest interactions between native populations and European explorers. "Let's focus more on issues of first contact."