Convoy Hi-71

Port side view of USS Spadefish in May 1944.

Date	August 18–19, 1944
Location	South China Sea
Result	United States victory

Belligerents

United States

Japan

Commanders and leaders

Glynn R. Donaho

Rear Admiral Sadamichi Kajioka

Strength

9 submarines

1 escort carriers
3 destroyers
9 kaibōkan
13 merchant ships

Casualties and losses

1 submarine sunk

~8,000 killed
7 merchant ships sunk
1 escort carrier sunk
2 destroyers sunk
3 kaibōkan sunk

Convoy Hi-71 (ヒ-71) was one of the World War II Hi convoys of fast tankers and troop transports from Japan to Singapore. The heavily defended convoy was specially loaded with reinforcements for defense of the Philippines, and encountered a wolfpack of United States Navy submarines in the South China Sea after being scattered by an August 1944 typhoon. Personnel losses were high because heavy seas prevented rescue of crewmen from sunken ships.

Japanese shipping through the South China Sea carried much of the food sustaining the Japanese population, the petroleum fueling Japan's aircraft and warships, and the raw materials for World War II. Japanese aircraft and warships patrolled South China Sea shipping lanes from bases in the Philippines; and loss of those bases would threaten the flow of resources needed to defend the Empire of Japan.

As Allied forces converged to fulfill Douglas MacArthur's promised return, Japan implemented Operation Shō to defend the Philippines. Convoy Hi-71 carried Imperial Japanese Army troops, weaponry and supplies from the home islands of Japan to reinforce the Philippines. The convoy left Moji on 8 August 1944 accompanied by the 6th Escort Group of two destroyers and five kaibōkan with an escort carrier embarking the 931st Air Group detachment of a dozen Nakajima B5N "Kate" attack planes. As the convoy departed the Mako naval base in the Pescadores on 17 August, it was reinforced by another destroyer and four kaibōkan to counter United States submarines operating in the Luzon Strait.

...
Wikipedia