Information on the old "S" Boats, and here he tells us:

USN submarines sank twenty-one Japanese submarines as well as two German U-Boats

British RN submarines sank two Japanese I-Boats, sixteen German U-Boats and eighteen Italian submarines;

Other Allied submarines sank four German U-Boats and one Italian submarines,

Japanese submarines sank one British, one Dutch and one American submarine,

All submarines sunk were destroyed while on the surface or in the act of surfacing or diving except for one;

Know which German U-Boat was detected and sunk by another submarine while both submarines were completely submerged? And what was the other submarine?