Technically, ships can also switch off from the AIS tracking device - then marinetraffic.com does not show the ship's movement.
Police and Border Guard Board: we can only observe
However, the port news portal states that the anchorages outside Russian waters are not intended for mass parking of tankers, which could jeopardize maritime safety in the Gulf of Finland. The “parking lot” in Estonian waters is not even an official anchorage area.
"The Maritime Surveillance Center of the Police and Border Guard Board (PPA) monitors ships which have been anchored or are drifting in the area waiting to enter the port,” confirmed Rene Hartõkainen, the leading border officer of the PPA's maritime security group. “The ships are in the Estonian economic zone, where they do not need to apply for the coastal state’s permission to anchor, to coordinate anything or even notify the state.”
According to Hartõkainen, the PPA monitors that ships in the area would not drift into the territorial waters. “There have been some incidents in the past,” he said. “In such cases we will contact the ship's crew immediately and direct them back to the exclusive economic zone (EEZ).”
In the course of routine monitoring, the PPA also monitors the occurrence of possible marine pollution. The use of the EEZ is governed by the EEZ Act and the United Nations Convention on the Law of the Sea (UNCLOS).
"The PPA has the right to inspect, obtain information from or detain vessels operating in our exclusive economic zone if the vessel's crew has committed an infringement, such as causing pollution, engaging in illegal fishing or other natural resources gathering, or conducting illegal research. If no violations have been committed, the PBGB has no right to limit the time the ship stays at anchor or to ask about the reason for staying at anchor,” Hartõkainen noted.