The New Adventures of Jonny Quest (1986)

S1E5 Forty Fathoms Into Yesterday

The Quest team embarks on a mission to retrieve a World War II German U-boat that vanished without a trace in 1945. However, their search takes an unexpected turn when they uncover a time machine hidden within the submarine. This device sends them hurtling back to the year 1945, leaving them stranded in the past with no clear means of returning home.