Heroes of the Deep II

The crew of the BT2, the Ostseetaucher’s ship, must check the stability of the FINO 2 research station between Rügen and Denmark. At a depth of 18 meters, they are tasked with measuring the thickness of the 15-year-old, rusting steel structure. Meanwhile, a salvage team near Usedom is working to remove scrap and munitions from a former military harbor basin. With zero visibility, diver Jan has to feel his way forward, inch by inch.

In the Hanseatic city of Wismar, an aging floating dock is due for inspection. But during what seems to be a simple job, diving trainee Justus loses his orientation underwater. Meanwhile, at the marina in Kröslin, diver Tobi uses a four-meter-long pipe and probe to drill through the harbor basin to give the green light for the construction of floating houses. In the process, he briefly finds himself in a precarious situation.

Off the coast of Rostock Rosenort, the Ostseetaucher crew anchors alongside a research team from the University of Rostock. At a reef, they deploy special seagrass mats in the hope of achieving a breakthrough in the fight against climate change. Meanwhile, another dive team heads beneath a nearly 170-meter-long ferry in Warnemünde to inspect it for damage. With a 30-meter rotor sail being installed at the same time, the job quickly becomes a test of patience for everyone involved.

The controversial construction of the Fehmarn Belt Tunnel and its impact on the marine environment are examined by the Baltic Sea divers off Puttgarden using an underwater robot. A sudden change in weather and strong currents make their task even more difficult. Meanwhile, another dive crew is working tirelessly to save a 54-year-old fish sandwich cutter from rusting away and needing an expensive shipyard visit.

On the island of Rügen, the BT2 crew anchors for several days at Germany’s longest outer pier, in the port of Sassnitz. Here, a 600-meter-long pipe is set to be laid into the seabed of the Baltic Sea to establish a fiber-optic connection between Germany and Denmark. With strong winds and waves forecast to reach 1.5 meters, the project risks becoming a safety hazard, forcing dive supervisor Frank Diestel to make a tough decision.

In the Rostock city harbor, the Baltic Sea divers are tasked with sealing a stormwater outlet using a canal balloon. It quickly becomes clear that the shaft cannot be accessed from the water side, forcing diver Frank to descend through a narrow manhole entry. At the Nienhagen Reef, another Ostseetaucher crew teams up with researchers and developers to test an autonomous diving robot shaped like a manta ray. This innovation is designed to support divers’ work in the future and search the Baltic seabed for munitions. But the saltwater takes its toll.