At the end of each month, Indy states the tonnage the Allied navies lost for that month to U-Boats and other commerce raiders in the Battle of the Atlantic.
However, the only mention of American submarine warfare I can remember being mentioned so far was the sinking of the Montevideo Maru by the USS Sturgeon in July. Was the American submarine warfare campaign against the Japanese not producing significant merchant ship losses for the Japanese by August/September 1942?