In the account of Fleet Problem XIII in 1932, Saratoga and Lexington went ahead of the battle fleet toward Pearl Harbor. Escorted only by destroyers, the carriers arrived before the expected battleship force. Exercise judges credited the raid with an overwhelming victory before the battleships could put to sea. Further exercises in 1938 and against San Francisco repeated the possibility of carrier attacks on defended naval bases.
Notable Point · 3:37-4:43
American exercises demonstrate carrier attacks on fleet bases
American Fleet Problems had already demonstrated how carriers operating ahead of battleships could surprise a defended base.