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Remotely Operated Vehicle

KAIKO is a world-class remotely operated vehicle (ROV) that excels in maneuverability and specializes in heavy work. The latest version of this ROV (4th generation, Mk-IV) has been repeatedly upgraded, and is mainly intended for deep sea surveys and marine resource surveys that require heavy work. The first ROV KAIKO collected such benthic organisms as Hirondellea gigas at a depth of 10,911 m in the Mariana Trench, and also discovered hydrothermal vent organisms in the Indian Ocean.


  • Deep sea surveys.
  • Perform heavy works necessary for submarine resources studies.

Principal specifications

Vehicle (KAIKO Mk-IV)
Length 3.0 m
Breadth 2.0 m
Height 2.6 m
Weight in the air 5.5 tons
Maximum diving depth 4,500 m
Payload weight 300 kg in air, 100 kg in water
Underwater speed 0.5~1.0knots
Research and observational equipment Two HD dome cameras, digital still camera, two high definition video cameras, compact monitoring video camera, lights, CTD, and dissolved oxygen meter
Navigational equipment Thrusters, obstacle detecting sonar, altimeter, inertial navigation system, Doppler Velocity Log, depth meter, monochrome rear view video camera, cable-monitoring camera, and ROV-Homer
Operational equipment Two manipulators with seven degrees of freedom
Cables Optical/power composite cables (12,000 meter-long primary cable with a diameter of 45 millimeters and 250 meter-long secondary cable with a diameter of 29.5 millimeters)

Activity records

Apr 2022 Vehicle began independent operation (launcher-less).
Apr 2016 The new KAIKO system started operation as one of facilities available for research exploration carried out for projects selected from among the proposals submitted from applicants in and out of JAMSTEC.
Nov 2013 KAIKO’s new Vehicle was constructed and named “KAIKO Mk-IV”.
Apr 2013 Retrieved temperature sensing loggers which had been installed in the focal area of the 2011 Tohoku earthquake.
Apr 2006 KAIKO’s new Vehicle “KAIKO 7000II” was constructed and launched.
May 2004 Restarted research operation after the ROV “UROV 7K” was converted into KAIKO’s Vehicle “KAIKO 7000”.
May 2003 KAIKO’s Vehicle was lost due to accidental breaking of the secondary cable during research off Shikoku.
Aug 2000 Discovered hydrothermal vents and communities at a depth of 2,450 meters in Indian Central Ridge.
Nov 1999 Discovered the engine wreckage of a Japanese rocket H-2 No. 8 on the sea floor at a depth of 2,900 meters off Ogasawara Islands during the search operation in which JAMSTEC took part after the rocket launching failure.
Oct 1999 Succeeded in connecting the measuring equipment with underwater cables on the sea floor at a depth of 2,150 meters in the Ryukyu Trench area.
May 1998 Collected specimens of the benthic amphipod, Hirondellea gigas (body length: about 4.5 centimeters), at Challenger Deep of Mariana Trench for the first time in the world.
Dec 1997 Identify a shipwreck as the passenger ship TSUSHIMA MARU which was sunk with schoolchildren onboard during the World War II off Okinawa, when participating in the search operation along with JAMSTEC’s deep sea research vessel KAIREI and ROV DOLPHIN-3K.
Feb 1996 Succeeded in collecting sediment samples together with microorganisms at a depth of greater than 10,000 meters (10,898 meters) at Challenger Deep of Mariana Trench for the first time in the world.
Mar 1995 Succeeded in diving to a depth of 10,911.4 meters at Mariana Trench during a sea trial with the support of the support vessel YOKOSUKA, and taking videos of various marine organisms including polychaetes and crustaceans living at great depths.

Sediment samples collected together with microorganisms

Benthic amphipod, Hirondellea gigas

Hydrothermal communities in the Indian Ocean