Some aircraft carriers, especially certain Japanese carriers during World War II, did not have the traditional "island" structure (the elevated command and control tower typically located on the starboard side of the deck). This design choice was largely driven by operational needs, technological considerations, and the particular philosophy behind carrier design at the time.
One of the primary reasons for the lack of an island on certain Japanese carriers, particularly early in World War II, was a focus on maximizing flight deck space. The absence of an island allowed for a much larger, unobstructed flight deck, which could accommodate more aircraft, increase sortie rates, and facilitate more efficient flight operations. The Japanese carriers such as the *Akagi* and *Kaga* were designed with large hangar spaces and extended flight decks, with the goal of giving their aircraft maximum operational capacity.
Additionally, early Japanese carriers, particularly those built before the war, were designed with a different approach to air operations compared to their Western counterparts. Without an island, the flight control operations were conducted from below deck or from a centralized position at the rear of the flight deck, where a dedicated bridge was located. This allowed for a smoother flow of aircraft during takeoff and landing, as there were fewer obstacles on the deck.
In some cases, like the *Shokaku* and *Zuikaku* carriers, Japanese designers eventually added islands, but these were often smaller and less obtrusive than the larger islands seen on American carriers, reflecting a balance between operational flexibility and the need for command and control.
Ultimately, the decision to omit the island was influenced by the unique operational philosophy and strategic goals of the Imperial Japanese Navy, with an emphasis on aircraft capacity and operational efficiency, which led to innovative, though sometimes unconventional, designs during the early years of World War II.