The minesweepers Crossbilland Condor were on patrol in the Defensive Sea Area in the early morning of 7 December 1941. At 0342 hours Ensign R. C. McCloy, Condor's officer of the watch, thought he saw a white wave which, when studied more closely through glasses, appeared to be the wake of a periscope. At 0357 Quartermaster Robert C. Uttrick signalled to the destroyer Ward on entrance patrol, "Sighted submerged submarine on westerly course, speed nine knots." Crossbill and Condor re-entered Pearl Harbor at 0458 when the anti-submarine net was opened for them. The supply ship Antares also saw what might have been a submarine and signalled Ward at 0630. The destroyer engaged and sank the intruder.