Patrol 1

11 Dec 1943- 30 Jan 1944

日高丸 Hidaka Maru

Patrol 2

22 Feb 1944- 15 Apr 1944

No Sinkings

Patrol 3

26 May 1944- 7 Jul 1944

Oi Maru (not credited to Batfish in JANAC)

長良川丸 Nagarakawa Maru

第五五十鈴川丸 Isuzugawa Maru #5 (small vessel not credited to Batfish in JANAC)

神威丸 Shini Maru (misread as Kamoi Maru in some sources; small vessel not credited to Batfish in JANAC)

Patrol 4

1 Aug 1944- 12 Sep 1944

第22号掃海艇 Minesweeper No. 22 (credited to Batfish in JANAC, not confirmed in Alden, and listed as sunk by aircraft on November 11, 1944 in Cressman and in Japanese sources)

五月雨 Samidare (not credited to Batfish in JANAC, but is in Alden and Japanese sources)

Patrol 5

8 Oct 1944- 1 Dec 1944

No Sinkings

Patrol 6

30 Dec 1944- 3 Mar 1945

Unknown Submarine, identified in various sources as I-41 (JANAC), or RO-55, or RO-115. (See note below)

呂-112 RO-112

呂-113 RO-113

Patrol 7

26 Jun 1945- 26 Aug 1945

Note on submarine claimed sunk on the evening of 9-10 Feb 1945

The "unknown submarine" claimed sunk by Batfish on Patrol 6 was thought to have been I-41, but that submarine was more likely sunk by USS Lawrence C. Taylor (DE-415) on November 18, 1944. Another possibility was the submarine RO-55, but it was more likely sunk by USS Thomason (DE-203) on February 7, 1945. A third possibility was the submarine RO-115, but it was more likely sunk by USS Ulvert M. Moore (DE-442) on February 1, 1945.

The sinking of a ship thought to have been an I-class submarine, as described in detail in Batfish's war patrol report, merits further investigation.

Current research credits Batfish with 8 ships totalling 9,971 tons. Included are Oi Maru, a small ship converted into a minesweeper and manned by a naval crew, and two small vessels, Nagarakawa Maru and Isuzugawa Maru #5, requisitioned by the Navy and operated by civilian crews. These three vessels were not credited to Batfish in JANAC. Not included the totals above are Minesweeper No. 22 and Patrol 6's "unknown submarine." The sinking of I-42 or any other submarine on February 9-10, 1945, is unverified.

JANAC - 6 ships, 10,230 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 8 ships and 9,971 tons sunk.

SORG credits with 13 ships and 51,100 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 Batfish

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.

NHHC: H-041-4: USS Batfish (SS-310) Sinks Three Japanese Submarines, February 1945

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.