were a numbered series of World War II trade convoys between Japan and Singapore. Merchant ships from Moji and Kaibōkan from Sasebo formed southbound convoys in Imari Bay to carry supplies for the Burma Campaign. Northbound convoys transported food, petroleum, and raw materials to Japan from the captured European colonies of the Dutch East Indies, French Indochina, and British Malaya and Burma. These convoys were initiated in mid-1943 to protect fast, high-value tankers and troopships from the improved effectiveness of Mark 14 torpedoes carried by United States submarines.

Convoy routing was through the East China Sea, Formosa Strait, and South China Sea. Ships often joined or left convoys at the Formosan ports of Takao and Keelung, at the Mako naval base in the Pescadores, and at the Vietnamese ports of Cape Saint Jacques and Cam Ranh Bay. Some convoys stopped at Manila until MATA and TAMA feeder convoys between MAnila and TAkao enabled Hi convoys to avoid United States submarine wolfpacks in the Luzon Strait by hugging the Asian coast between Hainan and Shanghai.

Convoy dates NumberDirectionImari BaySingaporeNotesHi-1South10 July 194319 July 1943Hi-2North3 August 194323 July 1943Hi-3South19 July 19431 August 1943Attacked by on 22 JulyCressman, p.171Hi-4North15 August 19435 August 1943Hi-5South7 August 194319 August 1943Hi-6North3 September 194324 August 1943Hi-7South25 August 19436 September 1943Hi-8North21 September 194311 September 1943Hi-9South10 September 1943Terminated 21 September 1943 at Cape Saint JacquesHi-10North9 October 1943Originated 28 September 1943 at Cape Saint JacquesHi-11South25 September 19434 October 1943Hi-12North21 October 194310 October 1943Hi-13South12 October 194330 October 1943Hi-14North16 November 19433 November 1943Attacked by on 8 NovemberCressman, p.192Hi-15Did not sailHi-16Did not sailHi-17South28 October 194311 November 1943Hi-18North28 November 194315 November 1943Hi-19Did not sailHi-20Did not sailHi-21South20 November 194314 December 1943Hi-22Did not sailHi-23South1 December 194314 December 1943Hi-24North4 January 194419 December 1943Hi-25South11 December 194321 December 1943Hi-26North26 December 1943Hi-27South21 December 19432 January 1944Attacked by on 27 DecemberCressman, p.200Hi-28North17 January 19448 January 1944Hi-29South31 December 194315 January 1944Hi-30North12 February 194419 January 1944Hi-31South11 January 194420 January 1944Hi-32North4 February 194425 January 1944Hi-33South10 January 194423 January 1944Hi-34North10 February 194427 January 1944Hi-35Did not sailHi-36Did not sailHi-37South20 January 194429 January 1944Hi-38North13 February 19442 February 1944Hi-39South26 January 19449 February 1944Hi-40North13 February 1944Dispersed 24 February under attack by and Cressman, p.214Hi-41South1 February 194411 February 1944Hi-42North28 February 194416 February 1944Hi-43South11 February 19443 March 1944Hi-44Did not sailHi-45South16 February 194427 February 1944Hi-46Did not sailHi-47South21 February 19445 March 1944Attacked by on 4 MarchCressman, p.216Hi-48North25 March 194411 March 1944Attacked by on 18 MarchCressman, p.218Hi-49South23 February 194411 March 1944Hi-50North8 April 194415 March 1944Hi-51Did not sailHi-52Did not sailHi-53South8 March 194418 March 1944Hi-54North29 March 1944Merged with Hi-56Hi-55South19 March 19443 April 1944Attacked by on 2 AprilCressman, p.221Hi-56North24 April 19448 April 1944Merged with Hi-54Hi-57South3 April 194416 April 19441 April departure delayed by stormHi-58North3 May 194421 April 1944Submarine USS Robalo seen by aircraft from Japanese aircraft carrier Kaiyō and damaged by convoy escort 24 April 1944Hi-59South20 April 1944Terminated 2 May 1944 at ManilaHi-60Did not sailHi-61South3 May 194418 May 1944Hi-62North8 June 194423 May 1944Hi-63South13 May 194427 May 1944Attacked by on 24 MayCressman, p.230Hi-64North15 June 19446 June 1944Hi-65South29 May 194412 June 1944Attacked by and on 2 JuneCressman, p.231Hi-66North26 June 194417 June 1944Hi-67South22 June 19449 July 1944Attacked by on 29 JuneCressman, p.238Hi-68North3 August 194414 July 1944Attacked by , and on 26 JulyCressman, pp.243 & 244Hi-69South13 July 194431 July 1944Hi-70North4 August 194415 August 1944Hi-71South8 August 19441 September 1944Attacked by , , , , and Hi-72North28 September 19446 September 1944Attacked by , and on 12 SeptemberCressman, p.253Hi-73South25 August 19445 September 1944Hi-74North23 September 194411 September 1944Attacked by on 16 SeptemberCressman, p.255Hi-75South8 September 194422 September 1944Attacked by on 18 SeptemberCressman, pp.255 & 256Hi-76North26 October 19442 October 1944Hi-76A departed Singapore 12 OctoberHi-77South1 October 194412 October 1944Attacked by , , and on 6 and 7 OctoberCressman, p.260Hi-78North2 November 194420 October 1944Hi-79South26 October 19449 November 1944Subsidiary Hi-79A formed on 6 November 1944Hi-80North2 December 194417 November 1944Hi-81South14 November 19444 December 1944Attacked by , and on 15 and 17 NovemberCressman, pp.274 & 275Hi-82North9 January 194512 December 1944Attacked by on 22 DecemberCressman, p.282Hi-83South25 November 194413 December 1944Attacked by on 3 DecemberCressman, p.278Hi-84North13 January 194526 December 1944Hi-85South19 December 1944Terminated 4 January 1945 at Cape Saint JacquesHi-86North10 February 1945Originated 9 January 1945 at Cape Saint Jacques;attacked by Task Force 38 on 12 JanuaryCressman, p.288Hi-87South31 December 194423 January 1945Attacked by Task Force 38 on 16 JanuaryCressman, p.289Hi-88NorthMarch 194520 January 1945to 18 March 1945Sailed as ten independent small convoys;Hi-88H attacked by on 23 February,and Hi-88I by and on 20 and 21 MarchCressman, pp.297 & 304Hi-89South24 January 19458 February 1945Hi-90North4 March 194515 February 1945Hi-91South26 January 19458 February 1945Hi-92North11 March 194518 February 1945Attacked by on 25 FebruaryCressman, p.298Hi-93South29 January 194512 February 1945Hi-94North14 March 194523 February 1945Hi-95South31 January 194514 February 1945Hi-96North22 February 194513 March 1945Attacked by on 27 FebruaryHi-97South7 February 194515 February 1945Hi-98North27 February 1945Single ship convoy Ryoei Maru sunk by Blair, p.821

Sources

Notes