Divers Clearing a Gas Pipeline Route Found a 400-Year-Old Shipwreck in a German Lagoon

Divers sent to clear a patch of seabed for a new gas pipeline in northern Germany expected to find debris. Instead they came up with shoe soles, pulley blocks and a rusty anchor, the remains of a ship built roughly 400 years ago that nobody knew was there.

The wreck lay in the Bay of Greifswald, a sheltered lagoon on Germany's Baltic coast. A preliminary report in the International Journal of Nautical Archaeology, led by Michał Grabowski, an underwater archaeologist at the University of Warsaw, describes the rushed rescue dig carried out in 2023. "When I saw the collection of artifacts in the photograph, it occurred to me that they must have come from a wreck," Grabowski said.

With pipeline dredging about to start, a team of five made 22 dives in just over 12 days. Conditions were poor. The wreck sat about 7.5 meters (25 feet) down on a soft, silty bottom, and the slightest movement clouded the water. Only fragments of the hull survived: a single patch of outer planking about 7.5 meters long, plus loose frames and timbers scattered across the seabed.

Those pieces were enough to identify how the ship was built. Its planks overlapped like roof shingles, were fixed with iron nails and sealed with a mix of tar and animal hair, a method known as clinker construction. Tree rings in one timber showed the tree was felled between 1626 and 1639, placing the ship in the era of the Thirty Years' War.

The team documented more than 60 objects, including wooden stocks, rope, barrel staves and a hollowed-out oak trunk that probably served as the bilge pump. They also found carpentry tools, among them a hand-drill handle similar to those recovered from the Tudor warship Mary Rose, which suggests the ship carried a workshop for long voyages. Personal items were scarce: two shoe soles and a stitched leather strap. Animal bones show the crew ate pork and either mutton or goat.

One find has the researchers stumped. It is a flat clay brick pierced with a row of holes, lodged inside a block of oak, and no similar object is known. The report suggests it may have been an improvised tool for sharpening blunt chisels and drill bits. "I had no idea what it was, but I really wanted to solve the mystery," Grabowski said. "And I still very much want to."

How the ship sank is also unclear. Some timbers were burned, hinting at a fire, and two anchors plus a type of buoy used when an anchor was down suggest it may have been moored when it went under. Grabowski declined to guess further. "Otherwise, we risk creating an alternative history," he said. The ship's name, home port and destination remain unknown, and more of it may lie in an unsearched area to the east.

The pipeline was rerouted and the remains covered with sandbags. The find joins dozens of wrecks turned up in the bay as energy projects survey the seabed, each adding detail to centuries of traffic through a waterway that linked the Baltic to the Oder River. "I think it's like a little time capsule," Grabowski said.