The 5.5-ton Tallboy bomb is 6 meters (20 feet) long and was found during works in a channel running through the town of Swinoujscie to Szczecin. With an impact range of over 10 kilometers (6 miles), it is the biggest wartime bomb found in Poland's waters.
Agnieszka Muchla-Lagosz, a regional spokeswoman, said experts are discussing ways of removing the bomb and the possible need to evacuate all residents of Swinoujscie. Tallboy bombs were used from June 1944 by British forces to destroy especially hard structures. The region was then under German control and heavily bombed.