A group of German archaeologists have set up an underwater museum in the Baltic Sea by planting signs next to shipwrecks, crashed airplanes and other noteworthy areas of the ocean floor. The signs aim to deter vandals, careless tourists and amateur collectors and treasure hunters.
The practice began in response to the damage of maritime legacy by hobby divers and trophy hunters. The Baltic Sea seabed is home to around 1,500 marine monuments including not just shipwrecks and aircraft but even ancient settlements.
One of the underwater museum project's specific targets was to prevent the infiltration of a two-man U-boat that was officially designated as a war grave but continued to be subjected to attempts to enter it.
Additionally, the signs are also a convenient way to provide interesting information underwater even for those divers with no intention of touching or manipulating them.