Fast Carrier Task Force
Command of the "big blue fleet" was alternated with Raymond Spruance. Under Spruance the fleet designation was the Fifth Fleet and the Fast Carrier Task Force was designated "Task Force 58". Under Halsey the fleet was designated Third Fleet and the Fast Carrier Task Force was designated "Task Force 38". The split command structure was intended to confuse the Japanese and created a higher tempo of operations. While Spruance was at sea operating the fleet, Halsey and his staff, self-dubbed the "Department of Dirty Tricks", would be planning the next series of operations. The two admirals were a contrast in styles. Halsey was aggressive and a risk taker. Spruance was calculating, professional and cautious. Most higher-ranking officers preferred to serve under Spruance; most common sailors were proud to serve under Halsey.