However , later it was found that the U-boat was only damaged but had to be interned by Spain a few days later .
One of which was the Action of 21 May 1918 when she was credited with sinking a German submarine off Spain .
Later it was found that the U-boat was only damaged but had to be interned by Spain a few days later .
One of which was the Action of 21 May 1918 when she was credited with sinking a German submarine off Spain .