Patrol 1

25 Aug 1944- 9 Oct 1944

No sinkings

Patrol 2

15 Nov 1944- 5 Jan 1945

安国丸 Yasukuni Maru - Not credited to Razorback in JANAC. USS Segundo and U.S. aircraft also hit this vessel, which was beached and became a total loss.

JANAC gives Razorback shared credit with USS Segundo for the sinking of Kenjo Maru, although Alden believes an attack by USS Trepang (SS-412) is more likely to have caused the sinking

呉竹 Kuretake

Patrol 3

1 Feb 1945-26 Mar 1945

4 small unidentified vessels sunk by gunfire No sinkings credited to Razorback in JANAC

Patrol 4

7 May 1945-27 Jun 1945

No sinkings

Patrol 5

22 Jul 1945-2 Sep 1945

No confirmed sinkings, although Razorback damaged and possibly sank 8 small vessels by gunfire

Current research and Alden-McDonald credit Razorback with 2 ships totalling 6,614 tons, including shared credit with USS Segundo (SS-398) for the sinking of Yasukuni Maru. Razorback also sank 4 small unidentified vessels of unknown tonnage by gunfire on her third patrol, none of which were credited to Razorback in JANAC.

JANAC credits Razorback with 1ship of 820 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.

SORG credits Razorback with 13 ships and 17,900 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)

Archives of the Pacific Fleet Submarine Museum (PFSM)

War Patrol Reports - USS Razorback

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.

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/

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)

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.