Volume 21 contains additions and corrections to existing entries from Volume 6 of the World War II Sea War series. In Volume 21 you will find extensive additions to Japanese military and merchant ship movements, as Japan tried to consolidate her newly acquired Pacific empire. There is also new data on the Royal Indian Navy, German U-boats, and the Royal New Zealand Navy. In addition, the monthly General sections have been expanded to help form the context of the war, especially how world leaders made decisions from day to day. In particular, Volume 21 provides additional detail on the following events: Japanese attack on Ceylon and the Bay of Bengal-more information on the Japanese tactics that created the confusion aboard the Japanese aircraft carriers off Midway Island. The Battle of the Coral Sea-more detail on US and Japanese actions in the South Pacific as Japan began to secure its position in the Solomon Islands and on New Guinea Island. The Battle of Midway Island-more detail on the US and Japanese actions and an improved timeline of the USN air attacks on the Japanese Carrier Striking Force. The Japanese Invasion of Attu and Kiska Islands plus the air attack on Dutch Harbor, Alaska-an improved timeline and more detailed description of the Japanese air attacks. Operation HARPOON-more detail on Royal Navy and Italian Navy actions during the British attempts to feed Malta.