Polish Navy begins deflagration of five World War II aerial mines near Świnoujście

Discovery and mine specifications

Specialists from the 8th Coastal Defence Flotilla identified five unexploded British aerial naval mines on the seabed of the Bay of Pomerania. The ordnance was detected during seabed surveys commissioned by the Maritime Office in Szczecin at the construction site of a future breakwater for a new external port in Świnoujście. The mines lie at a depth of approximately 10 metres, roughly 1,000 metres from the breakwater of the Świnoujście liquefied natural gas terminal. Military analysts classified the cylindrical weapons, each about 3 metres long, as British Mark IV, Mark V, and Mark VI mines designed to react to acoustic and magnetic vessel signatures. The total mass of the five objects reaches nearly 3,500 kilograms, representing a combined explosive charge equivalent to 2,500 kilograms of TNT.

Lieutenant Commander Grzegorz Lewandowski described the destructive capacity of the unexploded ordnance during an operational briefing:

They contain from 350 to 550 kg of explosive material. In total, the five objects have an explosive charge with a TNT equivalent of approximately 2,500 kg.

Operational timeline and neutralisation method

The Polish Navy commenced the disposal operation on the morning of Monday, 5 October 2026, with naval vessels leaving port before 08:00. The mission is scheduled across four consecutive days, running through 8 October 2026 under the command of the 8th Coastal Defence Flotilla. Mine clearance divers from the 12th Minesweeper Squadron carry out the underwater disposal tasks, with initial work on the first explosive charge scheduled to begin between 09:00 and 09:30 on Monday. Several dozen sailors participate in coordinating the mission and securing the operating area. The military specialists utilise deflagration, a controlled thermal burnout of the explosive content without high-order detonation. This chemical burning method neutralises the ordnance while avoiding acoustic shockwaves and preventing physical damage to the surrounding Baltic marine ecosystem.

Safety zones and maritime restrictions

Authorities established security perimeters covering both maritime channels and coastal areas to protect the public and naval personnel during operations. A strict ban prohibits people from entering the water along a 16-kilometre stretch of coastline running from Ahlbeck in Germany across Świnoujście to Międzyzdroje. Pedestrians remain permitted to walk along the sandy beaches while police officers patrol the waterfront to enforce bathing restrictions. Maritime traffic faces an exclusion zone that bars watercraft from approaching within 821 metres of the disposal site, while the broader safety zone extends 8.8 kilometres out into the open sea. Port authorities in Świnoujście simultaneously enacted a temporary ban on commercial underwater and diving works across the harbour basin.

Infrastructure protection and participating agencies

The Government Centre for Security distributed mobile alerts on Monday morning to residents and visitors across Świnoujście and Kamień County, instructing them to follow local emergency directives. The multi-agency security effort involves the Polish Navy, the Police, the Border Guard, the State Fire Service, Territorial Defence Forces, and the Regional Directorate for Environmental Protection. Clearing the seabed is a required prerequisite for developing a new external port, which includes a container terminal and a 70-kilometre approach channel for vessels with a draught of up to 15 metres. Lieutenant Commander Grzegorz Lewandowski noted the persistent hazard these wartime remnants pose to local commercial maritime development.

Despite the passage of years, they still pose a real threat to the safety of navigation and future investments in this region.