AMSTERDAM, Netherlands, March 16 (UPI) -- The Dutch navy says it discovered a World War I German submarine, keeping the find a secret until relatives of those killed on board were traced and notified.
The U-boat was found in October 2009 by HNLMS Snellius, which was engaged in charting the sea about 40 miles north of Terschelling Island, Radio Netherlands Worldwide reported Wednesday.
It was first thought the object uncovered during hydrographical surveys was the Dutch submarine O-13, which disappeared in June 1940, but a closer investigation showed the submarine was much older.
A brass ID plate on the wreck identified the submarine as Germany's U-106, which sank sometime before 1918 during World War I. The number of sailors on board at the time it sank was not reported.
The discovery was kept secret for two years while German authorities confirmed the identification of the crew and located living relatives.
A spokesman for the Dutch navy said the submarine would not be raised but instead would be left on the sea bed and given official war memorial status.