Over the succeeding days, the boats observed several planes but contacted only a few fishing vessels and small patrol craft. This drought of targets continued until 11 July, when "Thresher" made radar contact with a group of six ships steaming on the Formosa-Luzon route. As she changed course to intercept, she dispatched contact reports to the other boats. "Guardfish" and "Apogon" picked up the contact, but "Piranha" could not. "Thresher" deployed to a position astern of the convoy, to trail the enemy group and be ready to pick off stragglers. "Guardfish" took the enemy's port flank, and "Apogon" maneuvered to the convoy's starboard quarter.