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Support Vessel YOKOSUKA

The support ship YOKOSUKA performs surveys of the deep-sea bottom by acting as a support ship for SHINKAI 6500, a large submersible research vehicle. SHINKAI 6500 is capable of diving to a maximum depth of 6,500 m in the world.
In addition, the ship has a variety of functions for clarifying the surface layer of the deep-sea bottom, fault topography and geological structure and can be used for comprehensive research and observation of the deep sea and ocean trench areas.


  • Support research dives of the manned submersible, SHINKAI 6500
  • Support research dives of the 4,000 m towed deep ocean floor survey system, DEEP TOW
  • Seafloor topography surveys
  • Sub-bottom profiling
  • Geophysical surveys
  • Sampling of seafloor sediments
  • Structural surveys of the deep-sea bottom
  • Deployment and collection of seismometers, mooring systems, etc.


Underwater communications equipment
YOKOSUKA features equipment for communicating with SHINKAI 6500 while it performs underwater surveys. This communications equipment utilizes sound waves to make transmissions. Sound waves travel at a speed of around 1,500 m per second in water, and transmissions from YOKOSUKA therefore take around four seconds to reach SHINKAI 6500 when it is operating at a depth of 6,500 m.
YOKOSUKA features an extraordinarily large hangar for a ship of its size. The hangar measures 9 m long, 2 m wide, and 3 m high, and is used for housing and performing repairs and modifications on SHINKAI 6500.
A-frame crane launch and recovery facility
A massive A-frame crane is installed on the aft deck of YOKOSUKA for launching and recovering the almost 26 ton SHINKAI 6500.

Underwater communications equipment
Underwater communications equipment


A-frame crane
A-frame crane

Principal specifications

Length 105.2 m
Beam 16.0 m
Depth 7.3 m
Draft 4.7 m
Gross tonnage 4,439 ton
Cruising speed Approx. 16 knots
Range Approx. 9,500 nautical miles
Accommodation 60 (45crew, 15 research personnel)
Main propulsion system Diesel engines: 2,206kW × 2
Main propulsion method Controllable pitch propeller × 2