In the North Atlantic, rescue workers are feverishly searching for a submersible that was on its way to the famous wreck of the “Titanic” with five people on board.

what we know

What is it about? The search is for the submersible “Titan”. The vehicle is operated by the company Oceangate Expeditions, which offers wealthy adventure vacationers and “Titanic” researchers a diving trip to the world-famous wreck for large sums of money. According to the company, this is one of very few boats that can transport people several thousand meters deep.

The occupants: It is confirmed that the British businessman and adventurer Hamish Harding is on board as well as the British-Pakistani business consultant Shahzada Dawood and his 19-year-old son as well as a well-known French “Titanic” expert. A family spokesman confirmed to the BBC on Tuesday that researcher Paul-Henri Nargeolet, known as ‘Mr Titanic’, is one of the five occupants. The identity of the fifth person on board has not yet been publicly confirmed.

The submersible: The 6.70 meter small and 10.4 ton “Titan” offers space for five people and is a very simple vehicle.

In fact, it is a submersible in the narrow sense, not a submarine, because it does not go in and out of ports under its own power. Rather, it is brought by its large escort ship “Polar Prince” to the place where the “Titanic” lies and then submerges for a few hours. In an emergency, the oxygen on the “Titan” will last for 96 hours, i.e. approximately until Thursday. How is the search carried out? The US Coast Guard in Boston is in charge and is coordinating with Canadian rescue workers, as Commander John Mauger said. Several aircraft and ships as well as buoys with sonar on board are in use, which can record sounds at a depth of up to almost 4000 meters.

Where to look: Near the wreck of the “Titanic”. The remains of the luxury liner that sank in 1912 lie at a depth of around 3800 meters and around 684 kilometers south of the Canadian island of Newfoundland.

What we don’t know

The submersible: It is unclear whether the boat has already been located. Only when the exact location is known can a possible rescue be tackled. Oceanologist Simon Boxall of the University of Southampton said communications in these marine regions are severely limited, according to the British news agency PA. In addition, there are few boats that can dive so deep and attempt such a complicated rescue mission.

The reasons: What happened to the submersible is in the dark. It is not yet known whether the vehicle may have become trapped between the “Titanic” remains or whether it was driven towards the surface. There is a large debris field around the wreck at depth. According to the experts, it could be a challenge for helpers to identify the boat there.

An alleged emergency call: There was initially no confirmation of reports of an alleged emergency signal that the submersible could have sent. The British news agency PA quoted oceanologist Simon Boxall from the University of Southampton as saying: “I don’t know first-hand but as far as I know they have received a signal from the submarine.”