Polish Navy to neutralize five WWII British sea mines near Świnoujście LNG terminal

Discovery near the LNG terminal

Five British air-dropped sea mines from the Second World War will be neutralized in the waters of the Pomeranian Bay near Świnoujście. The unexploded ordnance was detected during surveying work commissioned by the Maritime Office in Szczecin on the construction site of a future breakwater for a new outer port. The five cylindrical objects, categorized as Mark IV, Mark V, and Mark VI types, measure three meters in length and resemble torpedoes. They rest on the seabed at a depth of approximately 10 meters, located roughly 1,000 meters from the Świnoujście LNG terminal. Together, the five mines have a total weight of nearly 3,500 kilograms, with each unit containing between 350 and 550 kilograms of explosive material, amounting to a combined explosive yield of around 2,500 kilograms of TNT equivalent.

Maritime Office in Szczecin spokesperson Ewa Wieczorek described the function and remaining danger of the wartime munitions.

In wartime operations, mines of this type were dropped from aircraft to mine a given area and exclude it from navigation. They reacted to the acoustic and magnetic fields of passing vessels. Despite the passage of years, they still pose a real threat to maritime safety and future investments in this region.

Neutralization plan and military deployment

The military operation to clear the ordnance will commence on Monday, 5 October 2026, at 08:00 and continue through 8 October. Specialist clearance divers from the 12th Minesweeper Squadron, operating under the 8th Coastal Defence Flotilla, are tasked with neutralizing the five devices. The technical procedure will involve a combination of controlled burning of the explosive contents, known as deflagration, and direct underwater detonation. Several dozen naval personnel will take part in the disposal efforts at sea. Multiple civilian and regional agencies will assist the naval operation, including the Border Guard, the State Fire Service, the 14th West Pomeranian Territorial Defence Brigade, and the Regional Directorate for Environmental Protection.

Safety perimeters and coastal restrictions

Authorities have established safety zones across both maritime and terrestrial sectors to protect the public and surrounding infrastructure during the four-day clearance operation. The coastal exclusion zone stretches along the shoreline from the German resort town of Ahlbeck across Świnoujście to Międzyzdroje in Poland, reaching up to 8.8 kilometers into the sea. While municipal beaches will remain open to walkers on land, officials have imposed a total ban on entering the water, bathing, and practicing water sports throughout the restricted coastal strip. Maritime authorities have established a navigation exclusion zone of 821 meters around the exact neutralization site, alongside a prohibition on all commercial diving and underwater works inside the port.

Lieutenant Commander Grzegorz Lewandowski outlined the civilian safety measures enacted across the coastal region.

Safety zones and restrictions on navigation and the use of municipal beaches have been introduced, from Ahlbeck through Świnoujście to Międzyzdroje. During the operation, an absolute ban on entering the water will apply.

Infrastructure development in Pomeranian Bay

Residents and visitors located within the operational perimeter will receive warning alerts sent directly to mobile phones by the Government Centre for Security (RCB). The clearance of the seabed is a required safety precursor for planned maritime construction projects underway in the area surrounding the gas terminal. Polish authorities plan to build a new outer port featuring a dedicated container terminal adjacent to the existing LNG installation. The project includes the excavation of a new 70-kilometer-long approach fairway, designed to accommodate commercial vessels with a navigation draft of up to 15 meters.