The Republic of Japan Navy (日本海軍の共和国, Nipponkaigun no Kyōwakoku; abbreviated ROJN), or West Japanese Navy (西日本海軍, Nishinihon kaigun; abbreviated WJN), is the naval branch of the Republic of Japan Armed Forces, tasked with the naval defense of West Japan. It was formed following the dissolution of the Imperial Japanese Navy (IJN) after World War II and the division of Japan. The first Chief of Naval Operations was Admiral Juzo Okita who served as CNO from 1952-1958, and was succeeded by the Vice Chief of Naval Operations, Admiral Ryu Hijikata.
The ROJN has a large fleet and its main tasks are to maintain control of the nation's sea lanes, to protect against the Wake Island Association and People's Republic of China, and to patrol territorial waters. It has also stepped up its participation in League of Nations and Allied Pact peacekeeping operations and Maritime Interdiction Operations.
Fleet
The Republic of Japan Navy is one of the most modern in the world due to a practice of replacing ships after only 20-30 years, with few exceptions. The Republic of Japan Navy has six main naval bases: Fukuoka, Kagoshima, Kure, Maizuru, Okayama, and Sasebo.
Ships
- Invincible-class aircraft carrier (1) - 1985
- RJS Mutekiyo (CVL-02) - former HMS Bellerophon (R07)
- Hyuuga-class helicopter carrier (2) - 2009
- RJS Hyuuga (CVH-03)
- RJS Ise (CVH-04)
- Izumo-class helicopter carrier (2) - 2015
- RJS Izumo (CVH-05)
- RJS Iwate (CVH-06) - under construction
- Yura-class Utility Landing Ship (2) - 1981
- RJS Yura (LSU-4171)
- RJS Maizuru (LSU-4172)
- 1-Go-class Landing Craft (2) - 1988
- RJS Yusotei 1-Go (LCU-2001)
- RJS Yusotei 2-Go (LCU-2002)
- Osumi-class Tank Landing Ship (3) - 1998
- RJS Osumi (LST-4001)
- RJS Shimotaka (LST-4002)
- RJS Kunisaki (LST-4003)
- LCAC-class Air Cushioned Landing Craft (6) - 1998
- RJS LCAC-01 (LCAC-2101)
- RJS LCAC-02 (LCAC-2102)
- RJS LCAC-05 (LCAC-2103)
- RJS LCAC-04 (LCAC-2104)
- RJS LCAC-05 (LCAC-2105)
- RJS LCAC-06 (LCAC-2106)
- Hatakaze-class Guided Missile Destroyer (2) - 1986
- RJS Hatakaze (DDG-171)
- RJS Shimakaze (DDG-172)
- Kongou-class Guided Missile Destroyer (4) - 1990
- RJS Kongou (DDG-173)
- RJS Kirishima (DDG-174)
- RJS Myoko (DDG-175)
- RJS Choukai (DDG-176)
- Atago-class Guided Missile Destroyer (4) - 2007
- RJS Atago (DDG-177)
- RJS Ashigara (DDG-178)
- RJS Maya (DDG-179)
- RJS Takao (DDG-180)
- Kii-class Destroyer (2 UC) - 2020
- RJS Kii (DDG-181) - under construction
- RJS Oowari (DDG-182) - under construction
- Asagiri-class Destroyer (8) - 1988
- RJS Asagiri (DD-151)
- RJS Yamagiri (DD-152)
- RJS Yuugiri (DD-153)
- RJS Amagiri (DD-154)
- RJS Hamagiri (DD-155)
- RJS Setogiri (DD-156)
- RJS Sawagiri (DD-157)
- RJS Umigiri (DD-158)
- Murasame-class Destroyer (9) - 1996
- RJS Murasame (DD-101)
- RJS Harusame (DD-102)
- RJS Yudachi (DD-103)
- RJS Kirisame (DD-104)
- RJS Inazuma (DD-105)
- RJS Samidare (DD-106)
- RJS Ikazuchi (DD-107)
- RJS Akebono (DD-108)
- RJS Ariake (DD-109)
- Takanami-class Destroyer (5) - 2003
- RJS Takanami (DD-110)
- RJS Onami (DD-111)
- RJS Makinami (DD-112)
- RJS Sazanami (DD-113)
- RJS Suzunami (DD-114)
- Akizuki-class Destroyer (4) - 2012
- RJS Akizuki (DD-115)
- RJS Teruzuki (DD-116)
- RJS Suzutsuki (DD-117)
- RJS Fuyuzuki (DD-118)
- Asahi-class destroyer (1, 1 UC) - 2018
- RJS Asahi (DD-119)
- RJS Shiranui (DD-120) - fitting out
- Isokaze-class destroyer (1 UC, 3 UC) - 2021
- RJS Isokaze (DD-121) - under construction
- RJS Yukikaze (DD-122) - planned for construction
- RJS Tokitsukaze (DD-123) - planned for construction
- RJS Amatsukaze (DD-124) - planned for construction
- Abukuma-class Destroyer Escort (11) - 1989
- RJS Abukuma (DE-229)
- RJS Jintsu (DE-230)
- RJS Ooyodo (DE-231)
- RJS Sendai (DE-232)
- RJS Chikuma (DE-233)
- RJS Tone (DE-234)
- RJS Kako (DE-235)
- RJS Otonase (DE-236)
- RJS Minase (DE-237)
- RJS Yahagi (DE-238)
- RJS Sakawa (DE-239)
- 30DEX (8 planned) - 2022
- RJS Unnamed (DE-240) - planned for construction
- RJS Unnamed (DE-241) - planned for construction
- RJS Unnamed (DE-242) - planned for construction
- RJS Unnamed (DE-243) - planned for construction
- RJS Unnamed (DE-244) - planned for construction
- RJS Unnamed (DE-245) - planned for construction
- RJS Unnamed (DE-246) - planned for construction
- RJS Unnamed (DE-247) - planned for construction
- Oyashio-class Submarine (11) - 1998
- RJS Oyashio (SS-590)
- RJS Michishio (SS-591)
- RJS Uzushio (SS-592)
- RJS Makishio (SS-593)
- RJS Isoshio (SS-594)
- RJS Narushio (SS-595)
- RJS Kuroshio (SS-596)
- RJS Takashio (SS-597)
- RJS Yaeshio (SS-598)
- RJS Setoshio (SS-599)
- RJS Mochishi (SS-600)
- Souryuu-class Submarine (9, 3 UC) - 2009
- RJS Souryuu (SS-601)
- RJS Unryuu (SS-602)
- RJS Hakuryuu (SS-603)
- RJS Kenryuu (SS-604)
- RJS Zuiryuu (SS-605)
- RJS Kokuryu (SS-606)
- RJS Jinryu (SS-607)
- RJS Sekiryu (SS-608)
- RJS Seiryuu (SS-609)
- RJS Shoryuu (SS-610) - under construction
- RJS Unnamed (SS-611) - under construction
- RJS Unnamed (SS-612) - under construction
- Sagami-class Combat Support Ship (1) - 1979
- Futami-class Ocean Survey Vessel (2) - 1979
- RJS Futami (AGS-5102)
- RJS Wakata (AGS-5104)
- Suma-class Ocean Survey Vessel (1) - 1982
- RJS Suma (AGS-5103)
- Chiyoda-class Submarine Rescue Tender (1) - 1985
- RJS Chiyoda (AS-405)
- Towada-class Combat Support Ship (3) - 1987
- RJS Towada (AOE-422)
- RJS Tokiwa (AOE-423)
- RJS Hamana (AOE-424)
- Kurobe-class Training Support Ship (1) - 1989
- RJS Kurobe (ATS-4202)
- Hibiki-class Ocean Surveillance Ship (2, 1 UC) - 1991
- RJS Hibiki (AOS-5201)
- RJS Harima (AOS-5202)
- RJS Unnamed (AOS-5203) - under construction
- Asuka-class Experimental Testbed Vessel (1) - 1995
- RJS Asuka (ASE-6102)
- Nichinan-class Ocean Survey Vessel (1) - 1999
- RJS Nichinan (AGS-5105)
- Hashidate-class Yacht (1) - 1999
- RJS Hashidate (ASY-91)
- Tenryu-class Training Support Ship (2) - 2000
- RJS Tenryu (ATS-4203)
- RJS Tatsuta (ATS-4204)
- Chihaya-class Submarine Rescue Ship (2) - 2000
- RJS Chihaya (ASR-403)
- Hiuchi-class Support Ship (5) - 2002
- RJS Hiuchi (AMS-4301)
- RJS Suo (AMS-4302)
- RJS Amakusa (AMS-4303)
- RJS Genkai (AMS-4304)
- RJS Enshu (AMS-4305)
- Mashu-class Combat Support Ship (2) - 2005
- RJS Mashu (AOE-425)
- RJS Omi (AOE-426)
- Shirase-class Icebreaker (1) - 2009
- RJS Shirase (AGB-5003)
- Shonan-class Ocean Survey Vessel (1) - 2010
- RJS Shonan (AGS-5106)
- Muroto-class Cablelayer (1) - 2012
- RJS Muroto (ARC-483)
- Chiyoda-class Submarine Rescue Vessel (1) - 2018
- RJS Chiyoda (AS-404)
- RJS Chitose (AS-405)
- Sagami/Towada-class Replacement (4 planned) - 202X
- RJS Unnamed (AOE-427) - planned for construction
- RJS Unnamed (AOE-428) - planned for construction
- RJS Unnamed (AOE-429) - planned for construction
- RJS Unnamed (AOE-430) - planned for construction
- Kashima-class Training Ship (4) - 1994
- RJS Kashima (TV-3508)
- RJS Kashihara (TV-3509)
- RJS Katori (TV-3510)
- RJS Kashii (TV-3511)
- Shimayuki-class Training Vessel (3) - 1999
- RJS Shimayuki (TV-3513)
- RJS Shirayuki (TV-3517)
- RJS Setoyuki (TV-3518)
- Asashio-class Training Submarine (3) - 2002
- RJS Asashio (TSS-3601)
- RJS Hayashio (TSS-3606)
- RJS Fuyushio (TSS-3607)
- Niijima-class Minesweeper Controller (1) - 1981
- RJS Niijima (MCL-722)
- Uwajima-class Minesweeper (6) - 1990
- RJS Maejima (MSC-675)
- RJS Kumejima (MSC-676)
- RJS Makishima (MSC-677)
- RJS Tobishima (MSC-678)
- RJS Yugeshima (MSC-679)
- RJS Nagashima (MSC-680)
- Ieshima-class Minesweeper Controller (1) - 1990
- RJS Ieshima (MCL-728)
- Yaeyama-class Minesweeper (3) - 1993
- RJS Yaeyama (MSO-301)
- RJS Tsushima (MSO-302)
- RJS Hachijyo (MSO-303)
- RJS Kyosai (MSO-304)
- RJS Ishigaki (MSO-305)
- RJS Tomoshiri (MSO-306)
- Uraga-class Minesweeper Tender (2) - 1997
- RJS Uraga (MST-463)
- RJS Bungo (MST-464)
- Sugashima-class Minesweeper (12) - 1999
- RJS Sugashima (MSC-681)
- RJS Notojima (MSC-682)
- RJS Tsunoshima (MSC-683)
- RJS Naoshima (MSC-684)
- RJS Toyoshima (MSC-685)
- RJS Ukushima (MSC-686)
- RJS Izushima (MSC-687)
- RJS Aishima (MSC-688)
- RJS Aoshima (MSC-689)
- RJS Miyajima (MSC-690)
- RJS Shishijima (MSC-691)
- RJS Kuroshima (MSC-692)
- Hirashima-class Minesweeper (3) - 2008
- RJS Hirashima (MSC-601)
- RJS Yakushima (MSC-602)
- RJS Takashima (MSC-602)
- Enoshima-class Minesweeper (4) - 2011
- RJS Enoshima (MSC-604)
- RJS Chichijima (MSC-605)
- RJS Hatsushima (MSC-606)
- RJS Terushima (MSC-607)
- Awaji-class minesweeper (6 UC) - 2017
- RJS Awaji (MSO-307) - fitting out
- RJS Hirado (MSO-308) - under construction
- RJS Unnamed (MSO-309) - under construction
- RJS Unnamed (MSO-310) - under construction
- RJS Unnamed (MSO-311) - under construction
- RJS Unnamed (MSO-312) - under construction
- Hayabusa-class Patrol Ship (10) - 2002
- RJS Hayabusa (PG-824)
- RJS Wakataka (PG-825)
- RJS Otaka (PG-826)
- RJS Kumataka (PG-827)
- RJS Umitaka (PG-828)
- RJS Shiritaka (PG-829)
- RJS Tako (PG-830)
- RJS Shirohayabusa (PG-831)
- RJS Kamome (PG-832)
- RJS Ahoudori (PG-833)
Future Procurement
- Two Shōhō-class light aircraft carriers are under construction to replace the RJS Mutekiyō, which is reaching the end of its lifespan.
- 25DD-class Destroyer: New 5,000-ton destroyer program first revealed in the MoD's FY2013 budget request, DD-119 and a second in FY2014, DD-120. Seemingly an ASW optimised development of the Akizuki-class likely intended for Sea lines of communication duties rather than the escort of MIDAS destroyers as in the case of the Akizuki. Planned to cost even less to operate and maintain than the already low cost Akizuki-class, partly through the use of COGLAG [Combined Gas turbine Electric And Gas turbine] propulsion. ¥72.3 billion has been requested for the construction of the first unit in the class, and to respond to a reduction of Hatsuyuki-class destroyers
- 5400 tonnes Light Escort Destroyer project, also referred to as 'the next generation escort ship'. Program in existence since 2009, current plans are to start construction on the first of class by 2021 at the latest. Full scale R&D activities scheduled from 2011 onwards.
- Four MIDAS equipped guided missile destroyers are planned to join the fleet in 2018. They will have a standard displacement of 8,200 tons.
- Six fleet replenishment oilers and four fast combat support ships are under construction to supplement the four combat support ships currently in service.
- In late 2013, it was being reported that a new high speed small destroyer class was to be procured. Full displacement would be in the 3,000-ton range. No other details such as development history were immediately available, though it was implied that the vessels would optimized for Anti-surface warfare. Peacetime roles would be primarily outer island warning and surveillance.
- The Japanese government is reported to be considering the procurement of a corvette type vessel. Exact details are unknown, but press reports indicate it may be a trimaran.