The “BT2” ship travels to the Wohlenberger Wiek where divers Tobi and Andreas begin to clear a deep-sea area for later construction work. But with millions of tons of WWII ammunition still lurking in the Baltic, it’s a risky job.

The BT2 explores Danish territorial waters with the help of the VALOR ROV: the most modern diving robot of our time. The 80 kg device is equipped with first-class sensors, high-resolution cameras and a system that enables live images to be transmitted directly to land.

Within sight of Rügen, the Baltic Sea divers drop anchor to salvage lost plastic "ghost nets," which can prove deadly traps for sea creatures; diver Erik acts cautiously around the wreck of the fishing cutter Friedrich Engels that sank in 1973.

Together with research divers, the Baltic Sea divers try to capture unique images of harbor porpoises looking for food. They also work to salvage a 17-meter-long ship that has sunk deep into the silt of the harbor basin.