Patrol 1

19 Jul 1944 - 31 Aug 1944

長良 Nagara

第七大源丸 Daigen Maru #7

太東丸 Taito Maru - Not credited to Croaker in JANAC

山照丸 Yamateru Maru (listed as "Sansho Maru" in JANAC)

Patrol 2

23 Sep 1944 - 10 Nov 1944

神喜丸 Shinki Maru

白蘭丸 Hakuran Maru (listed as "Byakuran Maru" in JANAC)

月山丸 Gassan Maru (total loss) - Not credited to Croaker in JANAC

御影丸 Mikage Maru

Patrol 3

13 Dec 1944 - 12 Feb 1945

No sinkings

Patrol 4

12 Mar 1945 - 22 Apr 1945

Patrol 5

15 May 1945 - 5 Jun 1945

第144号交通艇 Shuttleboat #144 (listed as 第154号交通艇 in Japanese Wikpedia) - Not credited to Croaker in JANAC. Alden uses the translation Communication Ship #144 Go.

研海丸 Kenkai Maru -89 ton Submarine Chaser, listed in some sources as sunk by Croaker. Not credited to Croaker in JANAC nor in Alden; more likely sunk by aircraft on 20 November 1944. Not included in totals below.

第146号交通艇 Shuttleboat #146 - Not credited to Croaker in JANAC. Alden uses the translation Communication Ship #144 Go.

Patrol 6

1 Jul 1945 - 13 Aug 1945

No Sinkings

10 ships, 24,893 tons, including Gassan Maru, a constructive total loss. Taito Maru, Shuttleboat #144, and Shuttleboat #146 were small vessels often not included in sinkings, and not credited to Croaker in JANAC.

JANAC - 6 ships, 19,710 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 with 10 ships and 24,892 tons sunk.

SORG credits Croaker with 11 ships and 37,200 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 Croaker

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.