<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 Hittokapu Bay on Kasatka (now Iterup) Island in the Kurile Islands, 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> <P> Before the attack commenced, two reconnaissance aircraft launched from cruisers Chikuma and Tone were sent to scout over Oahu and Maui and report on U.S. fleet composition and location . Reconnaissance aircraft flights risked alerting the U.S., and were not necessary . U.S. fleet composition and preparedness information in Pearl Harbor was already known due to the reports of the Japanese spy Takeo Yoshikawa . A report of the absence of the U.S. fleet in Lahaina anchorage off Maui was received from the fleet submarine I - 72 . Another four scout planes patrolled the area between the Japanese carrier force (the Kidō Butai) and Niihau, to detect any counterattack . </P>

What american ships were sunk at pearl harbor