It has been estimated that three million shipwrecks lie scattered on the seabed around the world. Most of them will never be found, but since the 2010s, searchers have been uncovering even the oldest and deepest wrecks. What’s behind the acceleration in discoveries?

According to David L. Mearns, author of The Shipwreck Hunter: A Lifetime of Extraordinary Discoveries on the Ocean Floor, shipwreck hunting has become more fruitful for a couple key reasons. First, records around the world have been digitized and so are more easily accessed. And secondly, underwater remote technology has advanced so that the actual work for searching for wrecks has become much more efficient.

Generally, most wreck-finding missions begin with scouring through archives—before anyone goes to sea. “If you do it professionally,” Mearns says, “the questions you ask yourself are: Can it be found? Can it be found in a reasonable time with a definable budget?”

That said, Mearns—who has found 26 major shipwrecks around the world— acknowledges that even painstaking research has become significantly easier.

“A lot of records are being digitized so you don’t necessarily have to visit every archive yourself,” he says. “What I can do in an archive in a day used to take me at least a week or two, and that’s just the efficiency of the archives.”

Once the research reveals ideal hunting ground, explorers have much better tools on hand to then carry out the search. In particular, Mearns notes, Autonomous Underwater Vehicles (AUVs) and Remote Operated Vehicles (ROVs) allow explorers to penetrate to almost any depth in the ocean. These vehicles also enable explorers to expand their targeted search zones.

“We can cover a lot of ground in terms of searching, we can expand the search area if the clues aren’t very good or vague, so it opens the door for more wrecks being found,” he says.

The March 2022 discovery of the wreck of Ernest Shackleton’s Antarctic expedition ship Endurance owed a great deal to the use of cutting-edge technology and a search vessel capable of swatting aside ice with an ease of which Shackleton could only dream in 1915. That vessel, the SA Agulhas__, was built in 2012 to supply South Africa’s Antarctic bases and was perfectly equipped to fight its way through the notoriously challenging sea ice of the Weddell Sea, where Endurance had been crushed 107 years before.

At 440 feet long and almost 13,000 tons, it is three times longer and 37 times heavier than the doomed vessel it found on the Antarctic seabed. When it arrived in the approximate location of the Endurance wreck, it deployed a robot called Sabertooth, which was able to descend 10,000 feet, using sonar to scan for the wreck and cameras to film it, all while the Agulhas blasted its propellers to keep the immediate area free of ice and its crew checked satellite data to guard against the ice’s encroachment.

But the Agulhas was able to target the approximate location in the first place because of diligent measurement-taking and recording by the Endurance captain, Frank Worsley, when the ship went down on November 21, 1915. Although Worsley was not, of course, able to record the ship’s position with the pinpoint accuracy granted by today’s GPS systems, his calculations carried considerable weight because of his deserved reputation as a master navigator.

Worsley guided the Endurance’s boats from the ice floe on which the crew was stranded to Elephant Island, where most of them waited while Worsley, Shackleton and four others took one of the boats to find rescue on South Georgia, which they reached after 16 days of battling storms and waves, all while Worsley methodically recorded their positions and plotted their course.

Worsley’s navigational abilities provided everyone involved in the search for Endurance the confidence that the ship could be found; but even so, the explorers would have delved deep into the records for as much supporting evidence as possible.

The public response to the discovery of Endurance highlights an enduring public fascination with shipwrecks, which Mearns attributes to “an innate curiosity to discover something and solve what isn’t known. And we make those unknowns known. We’re bringing history to life. It’s rare on land to be able to uncover something that people never knew about. But because of the depth and the darkness of the oceans, there are literally hundreds of thousands of mysteries that remain to be uncovered.”

Below are just a few of the more high-profile shipwrecks discovered or identified this century, frequently as a result of archival research, modern technology, or a combination of both.

Endurance: The ship of the Imperial Trans-Antarctic Expedition became trapped in the ice of the Weddell Sea in February 1915 and was never freed. By October, Endurance began to buckle in the ice’s grip, and on November 2 it was crushed and sunk, remaining unseen by human eyes for 107 years.

Black Sea Shipwreck: Discovered in 2018 by a team from the Black Sea Marine Archeology Project, the vessel sank more than 2,400 years ago, 50 miles off the coast of Bulgaria. It is the oldest intact shipwreck ever found. “A ship surviving intact from the classical world, lying in over 2 km of water, is something I would never have believed possible,” Professor Jon Adams, the principal investigator of the team that found the wreck, said. “This will change our understanding of shipbuilding and seafaring in the ancient world.”

Esmeralda: This Portuguese carrack sank off the coast of Oman in 1503 while under the command of Vasco de Gama’s uncle Vicente Sodré. First discovered in 1998 and then extensively excavated by a team led by David Mearns between 2013 and 2015, it is the oldest shipwreck recovered from Europe’s Age of Exploration.

Gribshunden: The flagship of John, King of Denmark caught fire and sank in the Baltic Sea in 1495. There, it lay undiscovered until members of a local dive club came across it in the 1970s; unaware of its significance, they did not report it to archeologists until 2000, and not until 2013 was the wreck’s identity confirmed. Analysis of the timbers showed they were made from oak trees felled in the winter of 1482-1483. Considered one of the best-preserved shipwrecks of the period, it has slowly been revealing its secrets, with archeologists uncovering such details as well-preserved sturgeon stored in a barrel in the ship’s pantry.

Erebus and Terror: These two ships sailed out of the River Thames on May 19, 1845, carrying 128 officers and men under the command of Sir John Franklin, on a search for the Northwest Passage. When the ships failed to return, a series of expeditions was sent to find them. These expeditions uncovered evidence that the crew had all perished, and a note that revealed the ships had been abandoned in April 1848. But the vessels themselves were not found until Erebus was discovered in 2014, and Terror was found two years later—close to where Inuit oral tradition had long claimed they were.

The Queen Anne’s Revenge: Originally a French slave ship called La Concorde, this mighty vessel was captured in November 1717 by notorious pirate Edward “Blackbeard” Teach, who used it to loot multiple vessels off the Atlantic seaboard and even, in April 1718, blockade the port of Charleston, South Carolina. It hit a sandbar and sank off North Carolina that June; the wreck was discovered in 1996 and its identity confirmed in 2011.

The Black Swan: In May 2007, a Florida-based company called Odyssey Marine Exploration announced that, using underwater robots, it had discovered a shipwreck in the Atlantic that it codenamed “Black Swan.” The wreck yielded 17 tons of gold and silver coins, with an estimated value of $500 million. However, the government of Spain claimed that the wreck was the Nuestra Senora de las Mercedes, a Spanish frigate that sank off the coast of Portugal in 1804 following a battle with four British navy ships. After a protracted legal battle, the treasure was returned to Spain in 2012.