The Royal Australian Navy has seen action in every ocean of the world. It first saw action in World War I, in the Pacific, Indian and Atlantic oceans. Between the wars the RAN's fortunes shifted with the financial situation of Australia: it experienced great growth during the 1920s, but was forced to reduce its fleet and operations during the 1930s. Consequently, when it entered World War II, the RAN was smaller than it had been at the start of World War I. During the course of World War II, the RAN operated more than 350 fighting and support ships; a further 600 small civilian vessels were put into service as auxiliary patrol boats. (Contrary to some claims, however, the RAN was not the fifth-largest navy in the world at any point during World War II.)