At 10:27 on the morning of 24 October 1944, eight dive bombers from the carrier USS Intrepid tipped over above the Sibuyan Sea and went for the biggest target any of their crews had ever seen. Below them steamed Musashi, one of the two heaviest battleships ever built, with nine 46-centimetre guns and armour designed to shrug off almost anything.

Their first bomb hit the roof of her forward main turret and failed to penetrate. It was the most reassuring moment Musashi would have all day. By the time the sun set, wave after wave of American carrier aircraft had hit her with an estimated 19 torpedoes and 17 bombs, and at 19:36 she rolled over and sank.

Eighty-two years ago today, the Battle of the Sibuyan Sea answered the last remaining doubt in a question navies had argued about for two decades. Aircraft had already sunk battleships at Taranto, Pearl Harbor and off Malaya. But could they sink the heaviest, best-armoured battleship ever built, under way and fighting back?

The super-battleship

Musashi and her sister Yamato were the Imperial Japanese Navy’s answer to American industrial weight. They displaced almost 72,000 long tons fully loaded, carried nine 460 mm main guns, and were the heaviest and most powerfully armed battleships ever constructed. Musashi was built at Nagasaki and commissioned in mid-1942.

For two years she rarely fired her guns in anger. She served as flagship of the Combined Fleet, ferried troops and equipment, was torpedoed by an American submarine in early 1944, and came back from repairs bristling with extra anti-aircraft guns. At the Battle of the Philippine Sea in June 1944 she was not even attacked.

In October 1944 she joined Vice Admiral Takeo Kurita’s Centre Force for Operation Sho-1, Japan’s plan to smash the American landings at Leyte. Japanese carriers in the north would act as bait to lure the US carrier fleet away, while Kurita’s battleships forced their way through to Leyte Gulf. The force left Brunei on 22 October. The next day, the submarine USS Dace sank the heavy cruiser Maya, et Musashi took on 769 of her survivors.

Five waves over the Sibuyan Sea

On 24 October, a scout from Intrepid found Kurita’s ships crossing the Sibuyan Sea. The first strike of SB2C Helldivers et TBF Avengers arrived at 10:27. Two minutes after the bomb bounced off her turret, an Avenger’s torpedo struck her starboard side amidships. She took on some 3,000 tonnes of water, and counter-flooding brought her level again.

The Operations Room’s animated account of the Battle of the Sibuyan Sea, showing how the strikes on Kurita’s Centre Force unfolded.

The second wave from Intrepid did more harm. A bomb penetrated two decks and burst above an engine room, cutting power to one propeller shaft. Nine Avengers then attacked from both sides and put three more torpedoes into her port side. Her speed fell to 22 knots.

At 13:31, 29 aircraft from Essex et Lexington arrived. F6F Hellcats strafed her decks to suppress the gunners, Helldivers scored four bomb hits near the forward turrets, and four more torpedoes struck home. Her bow settled four metres lower in the water.

Two hours later, Helldivers from Entreprise dropped 1,000-pound armour-piercing bombs and scored four hits, one of which wiped out the entire forward damage-control team. More Enterprise torpedoes followed. Then, at 15:25, 37 aircraft from Intrepid, Franklin et Cabot delivered the final blow: 13 bombs and 11 torpedoes. Speed fell to 6 knots, and for a time the rudder jammed.

“Prepare to abandon ship”

Kurita had no choice but to leave her behind with a small escort. Her crew fought for hours, flooding engine and boiler rooms to correct a list that kept growing. The engines stopped before she could be beached. At 19:15 the list reached 12 degrees and the crew was told to prepare to abandon ship; fifteen minutes later, at 30 degrees, they went over the side.

Musashi capsized at 19:36. Her captain, Rear Admiral Toshihira Inoguchi, chose to go down with her. Destroyers rescued 1,376 of her 2,399 crew. Her gunners did not go down quietly: the attack-by-attack record lists at least ten American Avengers and Helldivers shot down during the strikes on her.

The sinking did not end the battle, but it shaped it. Kurita’s force turned back for a time, and Admiral William Halsey, believing it beaten, took his carriers north after the Japanese decoy force. That decision set up the desperate Battle off Samar the next morning, one of the most famous stands in US Navy history.

Found a kilometre down

For seven decades nobody knew exactly where Musashi lay. In March 2015, Microsoft co-founder Paul Allen announced that his team aboard the yacht Octopus had found the wreck in the Sibuyan Sea, about a kilometre down, after eight years of research using records from four countries.

The footage showed that she had not gone down in one piece. The ship had blown apart underwater, scattering debris across the sea floor: the bow upright, the stern upside down, the superstructure lying separately on its side. On the bow, a round mount marked where the imperial chrysanthemum crest had been.

Six months after the Sibuyan Sea, in April 1945, Yamato died the same way, sunk by American carrier aircraft during Operation Ten-Go. The two greatest battleships ever built never got the gunnery duel they were designed for. They were beaten by single-engine aircraft flown by young men from flight decks they could not see.

Footage from Paul Allen’s 2015 expedition to the wreck of Musashi on the floor of the Sibuyan Sea.

Billy Mitchell had argued it in the 1920s, bombing old battleships at anchor. On 24 October 1944, US Navy aircrews proved it against the most heavily armoured warship ever to put to sea. If the battleship era needed a final verdict, it was delivered in the Sibuyan Sea.

Sources: Wikipedia (Japanese battleship Musashi; Battle of Leyte Gulf), US Naval History and Heritage Command, Associated Press, NPR, RNZ