During a government research mission researchers stumbled upon what they believe to be a 700-year-old shipwreck at the bottom of Norway’s largest lake, Mjøsa, reported Live Science.
The Norwegian Defence Research Establishment launched Mission Mjøsa after officials discovered unexploded bombs from World War II in the lake. They quickly drew up a plan to carefully map the lake bed to track the presence of these bombs and study their potential health effects on the water, as the lake provides 100,000 people with potable water.
Though previous research missions have turned up 20 shipwrecks in this lake, this was the first time that the deepest parts of the lake—some 1,350 feet deep—were explored with sonar technology.
“We only have the acoustic [sonar] images of the wreck,” Øyvind Ødegård, a maritime archaeologist, told Live Science. “But it appears from the data that there is the outline of something that possibly could be a stern—and if that’s the case, then that doesn’t really appear until the 1300s.”
Another clue to the ship’s age can be found in its construction, a style called clinker. In clinker ships, planks of wood are not joined side by side, like in the more common carvel style, but rather overlap, like a fan. Clinker-built boats are more hydrodynamic, flexible, and light than their carvel counterparts. However, they have their restrictions. Carvel ships or boats can be made using any quality of wood, whereas clinker boats require specific types of wood, and are typically crafted using axes that carefully condition the wood by splitting it along the grain. They are also somewhat more vulnerable to extreme weather, which was the downfall of this particular ship, found in the middle of the Mjøsa. Clinker-style boat building is a specialized craft, and as such has been designated a UNESCO intangible heritage by Nordic countries.