[1][2] With the shift to passive anti-submarine warfare, the collection of marine environmental data is required for efficient execution of maritime operations, and seafloor topography / sediment, tidal currents / geomagnetism, and water temperature / salt content, etc.

After that, one more ship was built in the 1983 plan based on 56 middle-aged businesses, and commissioned as JS Wakasa.

The cable tank is installed at the bottom of the ship below the bridge, and as the cable laying progresses, it becomes top heavy, so a seawater ballast tank is installed at the double bottom to ensure stability under any loading condition.

From, the second ship was changed to the in-line 8-cylinder Fuji 8L27.5XF diesel engine (single machine output 2,250 horsepower) connected to this lineage.

[5] For acoustic observation, various underwater radiation noise reduction measures have been taken inside the ship and the main engine also employs a highly elastic rubber joint and a variable pitch propeller driven via a reducer.