In April, "Enterprise" provided air cover for "Hornet" (CV-8) which was carrying 16 Army, twin-engine B-25s under the command of Lt. Col. James Doolittle. Ens. Vandivier made his closest approach to Japan on April 18 when the bombers rose from "Hornet" to make their daring one-way raid on Tokyo. Immediately after the launch, the two carriers and their escorts reversed course and cleared the area. Vandivier reentered Pearl Harbor on April 25. Five days later, "Enterprise" took the flyer to sea once more and raced to reinforce carriers "Lexington" (CV-2) and (CV-5) in the South Pacific. However, time and distance conspired to prevent Ens. Vandivier from participating in the Battle of the Coral Sea, which ended before his ship could reach the area. "Enterprise" was ordered back to Hawaii to ready herself for an even more important mission.