Treasures of underwater archaeology

The research divers in Germany systematically study coastal regions and inland lakes. They also work around the world, such as in Mexico and Indonesia. Historical sources, like old land and sea maps, or actual eyewitnesses, sometimes lead them to a discovery underwater. Coincidence, however, is the biggest factor in discoveries. GPS cannot help researchers, as it doesn't work underwater.

While recovering an abandoned "ghost net" on behalf of the World Wildlife Fund (WWF) in 2020, a team led by marine archaeologist Dr. Florian Huber discovered a valuable piece of German history: an Enigma, one of the legendary Nazi deciphering machines from World War II. It had become entangled in the trawl net.

Water acts as a preservative for ancient artefacts, such as wooden boats from the Roman Era. Some have been found sealed airtight on the seabed or at the bottom of a lake. However, the salt water in the North Sea and Baltic Sea aggravates the material more severely, leading the metal to rust. But on land, the wood would have long since rotted and turned to dust.

Remains of ancient shipwrecks or even submarines and military ships from the two World Wars are often found by research divers. Since many aircraft were also shot down over lakes or the sea, such finds are everyday business.

It is rare when marine archaeologists do not have to dive deeply to unearth an ancient treasure. In the spring of 2021, a dugout canoe from the Stone Age was recovered in the remote riverbed of the Old Rhine at Lake Constance. The boat corpus was very well preserved: The bank mud had preserved the wood airtight. The valuable "original boat" was discovered by a standup paddler.

The moment air hits the prehistoric material again, damage to the object is possible. So transport to the research laboratory must be conducted very carefully. This 8-meter-long (26-foot-long) dug-out canoe is 4,500 years old, so it is fragile cargo. It will be preserved and examined in detail. The researchers hope to gain insights into the early Bronze Age in the region.

The coastal regions of the seas or shore areas of large lakes were already populated in past millennia — as ports of call for trade. But the rise in sea levels or other external circumstances, such as storms, volcanic eruptions or natural catastrophes, caused them to sink into mud and water. Millennia later, ancient settlements have been recovered from the sea, such as here in Egypt.

One of the most spectacular underwater discoveries was undoubtedly the cave named after the professional diver Henri Cosquer. He discovered it in 1985 off the coast of Marseille. Named after him, the Cosquer Cave is considered by scientists to be one of the most interesting Paleolithic caves ever found.