Oyashio at Pearl Harbor in 2006
Class overview
Name	Oyashio (おやしお, Oyashio Current)
Builders	Kawasaki Shipbuilding Corporation Mitsubishi Heavy Industries
Operators	Japan Maritime Self-Defense Force
Preceded by	Harushio class
Succeeded by	Sōryū class
Built	1994–2008
In commission	1998–present
Planned	11
Completed	11
Active	9 (2 converted to training ships)
General characteristics
Type	Attack submarine
Displacement	2,750 tonnes (surfaced) 4,000 tonnes (submerged)
Length	81.7 m (268 ft 1 in)
Beam	8.9 m (29 ft 2 in)
Draught	7.4 m (24 ft 3 in)
Propulsion	Diesel-electric 2 Kawasaki 12V25S diesel engines 2 Kawasaki alternators 2 Toshiba motors 3,400 hp (2,500 kW) surfaced 7,750 hp (5,780 kW) submerged
Speed	12 knots (22 km/h; 14 mph) (surfaced) 20 knots (37 km/h; 23 mph) (submerged)
Complement	70 (10 officers)
Sensors and processing systems	Sonar: Hughes/Oki ZQQ-6 hull-mounted sonar, flank arrays, 1 towed array Radar: JRC ZPS 6 I-band search radar.
Armament	6 × HU-605 21 in (533 mm) torpedo tubes with 20 reloads for: Type 89 torpedoes UGM-84 Harpoon missiles

The Oyashio class is a series of Japanese diesel-electric attack submarines operated by the JMSDF. The submarines entered service in the late 1990s. The submarines are larger than the earlier Harushio class, to provide space for a flank sonar array.

Boats

There are a total of 11 boats in the class - the last boat was commissioned in 2008. Oyashio, Michishio, and Kuroshio share their names with World War II destroyers. Takashio shares a name with a ship from the third set of Yūgumo-class destroyers, of which none were built.

The first two boats, Oyashio and Michishio, have since been converted to training platforms.

On February 1, 2018, the Ministry of Defence's Maritime Staff Office revealed that seven of the service's 82-metre (269 ft 0 in) Oyashio-class submarines, which have a surface displacement of 2,800 tonnes – have already completed service-life extension work to date. The seven boats received extensive refits during their second and third maintenance cycles, which have been planned to bring the vessels to "almost the same level of that of the latest model Sōryū-class submarine, while extending their service lives.^[1]

Gallery

• 
  JS Mochisio (SS 600) departs Joint Base Pearl Harbor–Hickam to support Rim of the Pacific (RIMPAC) 2010 exercises.
• 
  Oyashio-class submarine.
• 
  Oyashio-class submarine.
• 
  JS Kuroshio (SS 596) at the Maizuru Naval Base.
• 
  JS Narushio (SS 595) pulls into Pearl Harbor for a scheduled port call before starting Rim of the Pacific (RIMPAC) 2008.
• 
  JS Yaeshio (SS 598) arrives at Naval Station Pearl Harbor for an annual training exercise.
• 
  JS Uzushio (SS 592) arrives at Joint Base Pearl Harbor–Hickam to begin their annual training exercise.
• 
  JS Mochishio (SS 600) arrives at Joint Base Pearl Harbor–Hickam to support Rim of the Pacific (RIMPAC) exercises.
• 
  Oyashio-class submarine profile