This shipwreck is the worst in European post-war history: on the night of September 28, 1994, during a storm in the Baltic Sea, the ferry "Estonia" sank on its way from Tallinn to Stockholm. To this day, the real cause of the disaster is unknown. Rumors and speculation surround it, as there are a number of inconsistencies, writes ARD.
852 people died in the disaster, but many of the bodies were not recovered. The remains of the ferry are 80 meters underwater, about 35 km southeast of the Finnish island of Utø. The site is officially recognized as a cemetery.
A year after the shipwreck, the governments of the surrounding countries Sweden, Estonia and Finland signed an agreement to ban diving around the wreck of the "Estonia" - so as not to disturb the peace of the dead. In the meantime, there were plans to remove the sunken ship with a concrete sarcophagus, but they were dropped due to protests from the relatives of the dead and due to fears that further investigations could make it difficult to identify the cause of the disaster. "Estonia" continues to lie at the bottom of the sea.
A training ground for the Russian military
However, it is obvious that unauthorized visits are periodically made to the wreck: investigations by the German media WDR, NDR and "Süddeutsche Zeitung" have established that NATO has information about the use of the wreck of the "Estonia" as a training ground for Russian submarine operations and possibly a hiding place for spy equipment.
According to the German media investigation, many NATO member states have information that several years ago technical devices were placed on the remains of the ferry that can guide underwater drones and robots with extreme precision. Western intelligence circles suggest that Russian military units were actively operating there.
In addition, there is a suspicion that Russia could use this prohibited zone in the middle of the Baltic Sea to hide its own sensor equipment there, through which it could record the so-called signatures of NATO warships and submarines, i.e. their specific noises and other characteristics.
Russia's position is aggressive
The location of the wreckage in the Baltic Sea between Sweden, Finland and the Baltic states is ideal for covertly collecting this type of information, military experts quoted by ARD say. In addition, Russia can operate there without being disturbed, as there is an official ban on diving. Another advantage is that the equipment installed on the ship is almost unobtrusive and can be installed stably - unlike the conditions on the sandy seabed.
In response to journalistic questions, Finland and Estonia stated that together with their allies they are closely monitoring what is happening in the Baltic Sea and their conclusions are that Russia has taken a more aggressive position since the beginning of its war against Ukraine.
GUGI - the Russian secret administration
In Russia, the Main Directorate for Deep-Sea Research, known by the abbreviation GUGI, is responsible for such underwater espionage as is allegedly being carried out on the remains of the "Estonia".
This administration shrouded in mystery has probably existed since the 1960s and is not subordinate to the Navy, but directly to the Ministry of Defense. Among its tasks are espionage and sabotage under water, for example, the study of critical infrastructure such as underwater cables and pipelines of European countries, writes ARD.
GUGI has a fleet of special ships that are officially declared as research and are equipped with equipment such as mini-submarines, underwater robots, powerful sonars and scanners to be able to spy under water. This so-called "academic fleet" also includes the ship "Yantar", considered in NATO circles to be one of Russia's most important spy ships.
One of the tasks of GUGI is also the recording of specific noises emitted by enemy ships, especially submarines. For this purpose, sensor systems such as underwater microphones (hydrophones) are used, which are installed in complete secrecy in the regions where the movement of the relevant vessels is assumed. NATO believes that Russia is using not only pseudo-research ships like the "Yantar" for these purposes, but also submarines, civilian ships - fishing or cargo, as well as underwater drones.
ARD also recalls in its publication the recent investigation into the secret underwater surveillance system "Harmony", with which Russia protects its nuclear weapons in the Arctic, for the construction of which the Russians used the most advanced Western technologies.
However, while "Harmony" is a widely deployed underwater warning system in Russian waters, according to Western security experts, it is considered certain that similar, albeit less extensive, espionage systems have been installed by Russia in other places in the world's oceans - possibly on the remains of the "Estonia" ship.
Studies by German media have established that underwater sensors were found in the Baltic Sea years ago, and not individual devices, but entire systems.
However, there is not much information on the matter: in early 2024, Lithuania officially announced that a Russian-type hydroacoustic sonar had been discovered in the Curonian Spit area, and even a photo of the sonar, which is apparently no longer functioning, was distributed. Information from Lithuania states that similar finds had been made years earlier not only there, but also in Latvia, Great Britain and Ireland.
Authors: Katharina Buss (ARD), Antonius Kempmann (ARD), Sven Lohmann (ARD), Merlin Menze (ARD), Alice Pesavento (ARD), Benedikt Strunz (NDR), Petra Blum (ARD), Florian Flade (WDR), Manuel Bewarder (WDR/NDR)