Lost at Sea
Cisco’s assigned patrol covered a large area in the South China Sea. Her expected position on 28 September 1943 was due west of Mindanao in the center of the Sulu Sea. Japanese records mention a combined ship and aircraft ASW action on that date slightly north and east of that position. The record reported the bombing of a submarine trailing oil, and that oil continued to surface until 10 October. Since no other submarine reported an attack in that position on that date, it is assumed that this attack involved Cisco. Nothing further was heard from Cisco or her crew of 76 men.
