This Day in Naval History - April 10
From the Navy News Sevice
1941 - USS Niblack (DD 424), while rescuing survivors of a torpedoed ship, depth-charged a German submarine; the first action of WW II between and German navies.
1963 - During diving tests, USS Thresher (SSN 593) lost with all hands (112 crew and 12 civilians) east of ,
1966 - River Patrol Boats of River Patrol Force commenced operations on inland waters of .