Patrol 1

7 June 1943-7 July 1943

相良丸 Sagara Maru

Patrol 2

24 Aug 1943-8 Oct 1943

甲陽丸 Koyo Maru

陽光丸 Yoko Maru

加智山丸 Kachisan Maru

弘和丸 Kowa Maru

大神丸 Daishin Maru

第三松成丸 Shosei Maru No. 3 - military vessel not credited to Harder in JANAC; some sources say vessel was sunk, but Alden says only damaged

Patrol 3

30 Oct 1943-30 Nov 1943

第十一鶚丸 Misago Maru No. 11 - military vessel not credited to Harder in JANAC, but is credited to Harder in Alden and other sources

鵜戸丸 Udo Maru

北江丸 Hokko Maru

北江丸 Nikko Maru

Patrol 4

27 Feb 1944-3 May 1944

雷 Ikazuchi

松江丸 Matsue Maru

Patrol 5

26 May 1944-3 Jul 1944

水無月 Minazuki

早波 Hayanami

谷風 Tanikaze

Patrol 6

5 Aug 1944-24 Aug 1944

松輪 Matsuwa - JANAC credits Harder (only) for this sinking; Alden lists Harder and Haddo as shared credit.

日振 Hiburi - JANAC credits Harder (only) for this sinking; Alden lists Harder and Haddo as shared credit.

佐渡 Sado - not credited to Harder in JANAC, but is in Alden. USS Haddo (SS-255) (only) is credited with this sinking in most sources, including the Imperial Japanese Navy Page for Sado.

USS Harder was lost on this patrol.

Current research credits Harder with sinking 18 ships, totaling 56,367 tons. These figures do not unclude Shosei Maru No. 3, but do include Misago Maru No. 11 and all three escort vessels (Matsuwa, Hiburi, and Sado) credited to Harder by Alden on her sixth patrol. USS Haddo is also credited with sinking two or possibly all three of these vessels in simultaneous or consecutive attacks.

JANAC credits Harder with 16 ships sunk totalling 54,002 tons. Note that the criteria JANAC used included all Japanese Naval vessels (although JANAC did not usually count warships less than 500 tons that were converted from merchant ships) and all Japanese merchant vessels of 500 or more gross tons known or believed to have been lost during the war. Differences between JANAC figures and current research are noted above.

Alden-McDonald credit Harder with 18 ships and 56,367 tons sunk.

SORG credits Harder with 20 ships and 78,200 tons sunk, plus partial credit for 1 ship of 2000 tons.

Wrecksite credits Harder with 18 ships and 54,002 tons sunk.

Japanese Naval and Merchant Ship Losses - JANAC on the NHHC website

JANAC on the Hyperwar website - https://www.ibiblio.org/hyperwar/Japan/IJN/JANAC-Losses/JANAC-Losses-6.html

SORG- http://archive.hnsa.org/doc/subreports-sorg.htm (Excel spreadsheet download)

SORG on combinedfleet.com

Archives of the Pacific Fleet Submarine Museum (PFSM)

War Patrol Reports - USS Harder - https://issuu.com/hnsa/docs/ss-257_harder

Monthly Losses of Combatant and Non-Combatant Vessels

太平洋戦争時の喪失船舶明細表（汽船主体）- Lost Vessel table during the Pacific War (merchant vessels)

Alden, John D., and McDonald, Craig R. - U.S. & Allied Sub Successes in the Pacific & Far East during WWII - Fourth Edition, 2009

Cressman, Robert - The Official Chronology of the U.S. Navy in World War II, Naval Institute Press, 2000.

Lockwood, Charles A., & Adamson, Hans Christian, Through Hell and Deep Water, Greenberg, 1956.

Sturma, Michael, Death at a Distance - The Loss of the Legendary USS Harder, Naval Institute Press, 2006.

Wrecksite - https://www.wrecksite.eu/wrecksite.aspx

Miramar Ship Index - https://www.miramarshipindex.nz/

Imperial Japanese Navy Page - http://www.combinedfleet.com/

Wikipedia Japan - https://ja.wikipedia.org/wiki/ハーダー_(SS-257)

Japan Center for Asian Historical Records - National Archives of Japan - https://www.jacar.go.jp/index.html

Official U.S. Navy Photos - Naval History & Heritage Command

Archives of the Pacific Fleet Submarine Museum (PFSM)

Imperial Japanese Navy Page - http://www.combinedfleet.com/

Japanese Merchant Ship photos - Wrecksite - copyright owners retain all rights. Photos used on this site will be taken down should the owner request their removal.