The "Enterprise" returned to Pearl Harbor on May 26. Ens. Vandivier and his shipmates began feverish preparations to meet an expected Japanese thrust at Midway Island. Two days later, his ship headed back to sea to take station off Midway Island. On the 30th, "Yorktown" put to sea to join "Hornet" and "Enterprise" some 235 miles (435 km) northeast of Midway. Planes from the three carriers searched diligently for the enemy force during the next three days; but it was a Midway-based PBY Catalina flying boat that made first contact with the Japanese invasion force on the morning of June 3, about 700 miles (1,300 km) from the island.