On September 6, 2022, barely three weeks before the explosions of the Nord Stream, the now designated sailboat is said to have left the port of Rostock in Germany.

The information has been revealed by German media, who have also had the boat's identity confirmed.

The sailboat is, according to the lessor's information, roughly 15 meters long.

- It is absolutely possible to use this type of boat, but it is not the first choice.

The big question is what the explosive devices looked like, there has been talk of them being large and then this sounds unlikely, says Oskar Frånberg, director of the National Underwater Technology Center at Blekinge University of Technology.

Could be "false flag" operation

There must have been six people on board, five men and one woman.

According to the German newspaper Die Zeit, some of them said they came from a Poland-based company with Ukrainian owners when they rented the boat.

But there is also speculation that it could be a so-called "false flag" operation, that is, that someone else laid out clues that point to Ukraine.

Exactly how the sailboat moved in the weeks after September 6 is still unknown, but both Danish and German police have questioned people who may have observed it.

Now they are investigating the boat's exact route, according to German Der Speigel.

The company that rents out the boat is not suspected of any crime, according to the police.

Danish island of interest to police

Among other things, the police have shown interest in which boats docked at the Danish island of Christiansö, which lies between Bornholm and the site of three of the detonations at Nord Stream.

- We have been in dialogue with the police, who asked for pictures of the ships that were in the harbor during the period 16-18 September, says Søren Thiim Andersen, administrator at Christiansö, to the Danish Ekstrabladet.

Carrying out a dive to a depth of 80 meters, which is where the Nord Stream exploded, is not particularly difficult for someone with the right training, according to Oskar Frånberg, but doing it from a sailboat is fraught with risk.

- I am skeptical, but it is feasible, says Oskar Frånberg.