<P> Striking the Pacific Fleet at anchor in Pearl Harbor carried two distinct disadvantages: the targeted ships would be in very shallow water, so it would be relatively easy to salvage and possibly repair them; and most of the crews would survive the attack, since many would be on shore leave or would be rescued from the harbor . A further important disadvantage--this of timing, and known to the Japanese--was the absence from Pearl Harbor of all three of the U.S. Pacific Fleet's aircraft carriers (Enterprise, Lexington, and Saratoga). IJN top command was so imbued with Admiral Mahan's "Decisive battle" doctrine--especially that of destroying the maximum number of battleships--that, despite these concerns, Yamamoto decided to press ahead . </P> <P> Japanese confidence in their ability to achieve a short, victorious war also meant other targets in the harbor, especially the navy yard, oil tank farms, and submarine base, were ignored, since--by their thinking--the war would be over before the influence of these facilities would be felt . </P> <P> On November 26, 1941, a Japanese task force (the Striking Force) of six aircraft carriers--Akagi, Kaga, Sōryū, Hiryū, Shōkaku, and Zuikaku--departed northern Japan en route to a position northwest of Hawaii, intending to launch its 408 aircraft to attack Pearl Harbor: 360 for the two attack waves and 48 on defensive combat air patrol (CAP), including nine fighters from the first wave . </P> <P> The first wave was to be the primary attack, while the second wave was to attack carriers as its first objective and cruisers as its second, with battleships as the third target . The first wave carried most of the weapons to attack capital ships, mainly specially adapted Type 91 aerial torpedoes which were designed with an anti-roll mechanism and a rudder extension that let them operate in shallow water . The aircrews were ordered to select the highest value targets (battleships and aircraft carriers) or, if these were not present, any other high value ships (cruisers and destroyers). First wave dive bombers were to attack ground targets . Fighters were ordered to strafe and destroy as many parked aircraft as possible to ensure they did not get into the air to intercept the bombers, especially in the first wave . When the fighters' fuel got low they were to refuel at the aircraft carriers and return to combat . Fighters were to serve CAP duties where needed, especially over U.S. airfields . </P>

Where did the planes that bombed pearl harbor take off from