1941

Attack on Pearl Harbor

Nagumo's Pearl Harbor Strike Force Departs Hitokappu Bay

Six carriers left at dawn under orders to turn back if a single merchant ship spotted them.

26 November 1941: weighing anchor in the Kurils

At 6:00 a.m. Japanese time on 26 November 1941, Vice Admiral Chūichi Nagumo's carrier strike force weighed anchor at Hitokappu Bay, on Etorofu in the Kuril Islands, and departed for Hawaii.

Its six carriers were Akagi, Kaga, Sōryū, Hiryū, Shōkaku and Zuikaku, accompanied by battleships, cruisers, destroyers, tankers and other support vessels, with more than 420 embarked aircraft. The National Park Service counts 33 warships and auxiliary craft.

In Japan it was already 26 November; on Washington's calendar the fleet left on the 25th.

Silent, and routed north

The force observed complete radio silence and used radio deception while taking a northern route chosen to avoid normal shipping lanes and reduce the chance of discovery.

That silence was not total across the navy: shore-based radio deception helped conceal the carriers' absence.

Planners accepted the stormy northern weather because bad weather and empty shipping lanes offered concealment.

Sailing under conditional orders

Nagumo's orders directed the force to proceed secretly to a standby point near 42° north and 170° west by the evening of 3 December — but to abort if it was discovered or if diplomacy succeeded.

Departure therefore did not mean Japan's final political decision for war had been made; the Imperial Conference took that decision on 1 December. Isoroku Yamamoto, commander-in-chief of the Combined Fleet, was the strike's principal naval advocate and planner.

By the end of 26 November the fully assembled force was at sea on a little-travelled northern route, undetected.

Sources

Researched 23 Aug 2026 8 sources 2 audit passes Date corrected

How this was checked

Researched from the web into a fact sheet, rewritten from that sheet, then audited against it by a different model. How the pipeline works →

Date corrected. The research places this at 1941-11-26.

What the sources leave uncertain

Because the force crossed the International Date Line, 6:00 a.m. November 26 in Japan corresponded to November 25 in Hawaii and Washington. This explains accounts saying it departed the day before the November 26 Hull Note.
The bay appears under several romanizations, including Hitokappu, Hitokapu and Hittokapu. It was on Etorofu/Iturup in the Kuril Islands.
Vessel totals vary according to whether submarine forces and particular auxiliaries are counted with Nagumo’s surface strike force; the National Park Service gives 33 warships and auxiliary craft.