More than 4,500 miles from home, Brendan Foley climbs out of a battered Fiat van and heads for the edge of the cliff up ahead. The sharp rocks are dotted with goat droppings and gorse, and he struggles to keep his footing as the wind screams past, so violent that he wonders for a moment if he’ll be blown right off the rocks. From as close to the edge as he dares, he looks down at the waves. The gales have turned the sea so white it looks like boiling milk.

The barren island of Antikythera is perhaps Greece’s most remote scrap of land, just over six miles long and two miles wide, a dot on the map between the east and west Mediterranean. It has just 30 or so permanent inhabitants, who live in white houses clustered around the island’s only harbor. When Foley, an archaeologist, arrived here with his team two weeks ago, they made an offering to Poseidon, pouring wine and olive oil into the ocean in the hopes of being granted calm waters. But instead, the sea has conjured brutal storms. To see just how bad the conditions are today, Foley has driven across the headland to a north-facing curve in the cliffs called Pinakakia.

Beneath the cliff, under 180 feet of churning water, are the remains of a ship that smashed against Pinakakia’s rocks 2,000 years ago. When this wreck was discovered in 1900, it yielded a priceless cargo—Greek statues, glassware, jewelry and a sophisticated device for modeling the cosmos so revolutionary that the science fiction writer and futurist Arthur C. Clarke later argued it could have sparked the Industrial Revolution more than a millennium ago. If the Greeks had been able to build on the technology, Clarke said, “By this time we would not merely be pottering around on the moon. We would have reached the nearer stars.” As the first wreck ever investigated, the Antikythera ship, as it’s now known, caught the world’s attention and gave birth to the field of marine archaeology.

Foley, 46, is easygoing and personable, as comfortable mingling with politicians and billionaires as with his colleagues at the Woods Hole Oceanographic Institution back in Massachusetts. He’ll need his good nature on this trip, as well as the streak of determination it often hides. He is convinced that many of the ship’s treasures are still in the sand, and he has returned to the site with the best technology that the 21st century has to offer to undertake one of the most ambitious underwater archaeology projects in history.

He’s spent the past decade building a partnership with Greek archaeologists, usually fiercely protective of their heritage, to become one of the only U.S. scientists allowed to work in the country’s waters. With Theotokis Theodoulou and Dimitris Kourkoumelis of Greece’s Ephorate of Underwater Antiquities, he has gathered the world’s top technical divers (supported by a team from the Greek Navy), gained the use of a state-of-the-art robotic submarine from Australia, and collected millions of dollars in research funds from private sponsors such as Greek billionaires and a Swiss watchmaker.

Donors provided a luxury yacht and a helicopter, and have even installed a 4G cellphone tower on the island so that the team has uninterrupted Internet. Most impressive of all, Foley has on loan the futuristic Exosuit—the world’s most advanced diving suit, essentially a wearable submarine worth $750,000—along with a Greek Navy ship to launch it from. The Exosuit is brand-new, and Antikythera is to be its first foray into the open sea.

Foley, a graduate of the University of Southampton in England and later MIT, learned from the best: deep-sea explorer Bob Ballard, who discovered the wreck of the Titanic in 1985. From 1997 to 2003, Ballard was a mentor for Foley, starting with an expedition to Skerki Bank, an area of open sea on an ancient shipping route between Sicily and North Africa. “It opened my eyes to archaeology as big science,” Foley says. That multimillion-dollar project, which uncovered four shipwrecks in 1997 alone, had a nuclear-powered research submarine, the remotely operated vehicle Jason and an accompanying TV crew.

Now it’s Foley’s chance to direct a comparable project of his own. It made headlines before the dives even started, but optimism is turning quickly to desperation. It is Monday, September 29, halfway through the four-week trip, and the team has dived on the wreck just twice since arriving—once to relocate the site and once with a metal detector, which yielded no significant hits. With the bad weather expected to continue, the helicopter is out of action. The yacht and navy ship (with the Exosuit on board) have fled to the Peloponnese. And Foley’s divers are high on the hillside above the harbor, huddling in a cockroach-infested set of rooms that pass for Antikythera’s only hotel. They’ve been sitting here for days, behind a truck that’s parked in front of the porch in a vain attempt to block the wind.

Foley, usually relentlessly upbeat, is unable to find any positive spin. “I’m at a loss,” he told me helplessly. “We may not get in the water again.”

In a few days, he has a big event planned on Antikythera’s neighbor, Kythera, the larger of the two islands, with hundreds of journalists, sponsors and politicians being flown from Athens on a luxury jet. (Champagne and canapés will be served even before the plane leaves the runway.) Foley has been looking forward to a triumphant announcement of spectacular finds—the biggest moment of his career so far—and the chance to win money for years of future work.

Now, he doesn’t know what he is going to say.

A pile of corpses. Naked. Rotting on the seabed. Elias Stadiatis was scared and breathless as he told his colleagues of the horror he had seen beneath the waves. It was spring 1900, and the small group of sponge divers had been blown off course by one of the region’s notorious storms. They sheltered in Antikythera’s harbor and, when the sea had calmed, looped around the headland.

The divers, led by sponge boat captain Dimitrios Kontos, were from the island of Symi in the eastern Aegean. Along with many thousands of other young men, they sailed to North Africa every spring and returned in the autumn, their tiny boats laden with sponges. The trade was booming thanks to the introduction of canvas diving suits with bronze helmets, which allowed them to dive deeper and longer than ever before.

Stadiatis was the first to dive that day, but he surfaced almost immediately, claiming he had seen dead people and horses on the seabed. Kontos, looking for himself, discovered instead a pile of statues from an ancient ship. The divers continued to their fishing grounds, but when they returned that autumn, Kontos reported the find to officials in Athens, presenting a life-size bronze arm as proof.

The Greek government, reeling from the humiliating loss in the Greco-Turkish War of 1897, hired the men to dive for more, hoping the mission would boost national pride. Over the next ten months, Kontos and his team, guided by archaeologists, salvaged all they could from the wreck. The depth made for dangerous work. The divers breathed air fed through a pipe from the boat above, and the bends was a serious risk, as was the carbon dioxide that, instead of being expelled into the water, became trapped in their helmets. The divers spent only three to five minutes on the seabed per dive, but by the time the work was done, two suffered paralysis and one was dead.

Kontos’ men brought up a breathtaking haul. One glass bowl was a delicate bluish green with carved olive branches. Others were made of hundreds of twisted coils. A wood and bronze couch featured a headrest decorated with lions and the bust of a woman wearing her hair in a bun. The huge marble statues had rough, pitted surfaces where sea creatures such as date mussels and marine bacteria had eaten away the stone. The bronzes were in better condition, including a six-foot-tall athlete now known as the Antikythera youth—one of the finest statues that survives from classical Greece.

Overall, the ship yielded one of the most impressive collections of treasures ever recovered from antiquity. Hundreds of ancient cargo ships have been excavated since, but only a handful of luxury items rival those from Antikythera: a load of marble columns and sculptures from a wreck near Mahdia, Tunisia; a bronze statue of Zeus in the act of throwing a thunderbolt, found off Greece’s Cape Artemision; ebony, ivory and ostrich eggs from a late Bronze Age ship that sank off Turkey’s Cape Gelidonya.

Absolutely nothing to this day rivals the small bronze device dubbed the Antikythera mechanism. The complexity of the machine’s gearwheels and dials led to claims that it was a modern instrument later dropped on the wreck site by chance, and even that it was made by aliens. Scholars studying its internal workings now understand that the device, dating to the first century B.C., modeled the undulating motions of the sun, moon and planets through the sky. Nothing close to its sophistication is known until the appearance of modern clocks in Medieval Europe, and it has revolutionized our understanding of what ancient craftsmen were capable of. Who exactly made this breathtaking machine? Why? And how did it end up on this doomed ship? These are open questions.

The items retrieved by the sponge divers were taken to the National Archaeological Museum in Athens, where many are on display today. Studies of the ship and its contents have since concluded that this was a Roman vessel that sailed between 70 and 60 B.C., carrying Greek treasures—some of which were centuries old when the ship sank—from the eastern Mediterranean westward. At this time, the Romans were gradually taking over the entire region, and they shipped boatloads of Greek artwork, including paintings, mosaics and sculptures, back home to decorate their luxury villas. For archaeologists today, the wreck is a time capsule, a single moment of history preserved. Like the tomb of an ancient pharaoh, it offers a unique window into a long-lost world.

The legendary marine explorer Jacques Cousteau recognized its value. With the scuba technology he invented, he led an expedition to Antikythera in 1976. Over five months, he dredged part of the wreck site and discovered hundreds of small items, including coins, glass pawns from a board game, jewelry and snail shells, probably the remains of food eaten by the crew. There were bones from at least four individuals, including a young woman, who may have been on the ship as a passenger (sparking theories that the Antikythera mechanism belonged to a princess traveling with her dowry). The area Cousteau investigated may have corresponded to the ship’s galley and cabins. What Cousteau didn’t find, however, was the hold.

So nearly 40 years later, Foley and his team are back, the first to dive the site since Cousteau, and the first ever to excavate it in a detailed, scientific way. It’s likely that many treasures remain. Half of the Antikythera mechanism is missing, for example, while many pieces of bronze statues, including arms, feet and weapons, were recovered without their torsos.

“When I go to the National Archaeological Museum, I always go straight to the Cape Artemision Zeus,” Foley says of the bronze statue found at a different wreck. We’re talking over breakfast, and he holds up his arms to emulate the statue’s athletic pose. “If we can make finds like that and they are shown in the museum, generations to come will be inspired.”