Polish Navy neutralizes two British World War II sea mines near Świnoujście port

Neutralization of World War II ordnance

Mine clearance divers from the Polish Navy's 12th Minesweeper Squadron neutralized two British Mark VI aerial sea mines in the Baltic Sea near Świnoujście on Monday, 5 October 2026. The operation began at 08:00, with divers completing the neutralization of the first mine by 10:00. The two devices together contained more than one tonne of explosive material. Military specialists neutralized the mines through deflagration, a controlled thermal burnout process designed to consume explosive material without causing a high-order detonation.

Lieutenant Commander Grzegorz Lewandowski, press officer for the 8th Coastal Defence Flotilla, described the outcome of the opening day:

Today we carried out an operation to neutralize two Mark VI air-dropped mines, which together contained over a tonne of explosive material. They were effectively neutralized through the deflagration method. We completely eliminated the impact of a potential explosion on the environment, nature, and nearby infrastructure.

The disposal operation is scheduled to run between 5 and 8 October, covering five British World War II mines (types Mark IV, Mark V, and Mark VI) discovered on the seabed at a depth of approximately 10 metres. In total, the five devices weigh nearly 3.5 tonnes and hold an explosive charge equivalent to roughly 2,500 kilograms of TNT, with individual mines containing between 350 and 550 kilograms of explosives. The remaining three mines are slated for disposal between Tuesday and Thursday.

Safety measures and coastal exclusions

To ensure public safety during the underwater operations, maritime and civil authorities instituted security zones along 16 kilometres of coastline stretching from Ahlbeck in Germany, through Świnoujście, to Międzyzdroje. The Director of the Maritime Office in Szczecin issued an order barring all individuals from entering the water between 08:00 and 15:00 on active disposal days, although public beaches remained open to pedestrians on land.

Maritime traffic faced strict restrictions throughout the operation. Vessels, including passenger ferries operating to and from Świnoujście, were prohibited from entering an 821-metre exclusion perimeter around the neutralization site.

West Pomeranian Voivode spokesperson Paulina Heigel detailed the inter-agency force deployed along the coastline to enforce the exclusion zones:

Over 50 sailors from the 8th Coastal Defence Flotilla, over 50 police officers, six firefighters, 18 Border Guard officers, 29 Maritime Office employees, three Wolin National Park employees, Municipal Police, and Forest Guard are involved in the operation.

Two German specialists from the State Office for Central Tasks and Police Technology, Fire and Disaster Protection of Mecklenburg-Western Pomerania also participated in securing the border coastline.

Infrastructure development near Świnoujście

The ordnance was detected during preparatory seabed surveys for a new outer breakwater, situated approximately one kilometre from the Świnoujście LNG terminal. The breakwater project is part of a planned commercial port expansion featuring a deep-water container terminal. The marine development also involves constructing a 70-kilometre approach fairway designed to allow access for vessels with drafts of up to 15 metres. Naval divers will resume underwater neutralization procedures at 08:00 on Tuesday morning.