Unmanned undersea vessel eyed to detect subs

  • Science and Technology Policy Japan
  • Drones

Unmanned undersea vessel eyed to detect subs

The government has begun to consider introducing unmanned underwater vehicles capable of detecting submarines and other vessels with a view to beefing up warning and surveillance capabilities against subs dispatched by the Chinese military or by other countries to the East China Sea, where the Senkaku Islands of Okinawa Prefecture are located.

The Defense Ministry intends to start developing prototype models in fiscal 2019 and aims to start operations using the unmanned vehicles in fiscal 2025.

The government plans to advance projects to further the use of unmanned underwater vehicles and also aircraft. When the National Defense Program Guidelines are revised at the end of the year, they will likely emphasize greater use of such vehicles.

The unmanned underwater vehicle the government envisages using in warning and surveillance activities is 10 to 15 meters in length and can be programmed to self-navigate in a certain area for several days or up to about a week. It will be given the ability to detect submarines and surface ships with its sonar, and also use its artificial intelligence to self-navigate and pursue these vessels.


As water temperature, salinity concentration, seabed topography and other factors have effects on warning and surveillance activities, and detecting submarines, the unmanned vehicles will be enabled to carry out oceanographic observations and gather necessary data.

The Defense Ministry has made an appropriation request of ¥4.2 billion in the fiscal 2019 budget for test production and aims to complete a model by fiscal 2024. The ministry intends to install highly efficient fuel cells to increase the duration of underwater operations. The unmanned vehicles will not be given attack capabilities.

According to the ministry, unmanned underwater vehicles for surveillance of submarines are also being developed by a U.S. company, and a prototype already exists. The U.S. Navy is said to be considering the introduction of this model.

With regard to development in Japan, its first domestically built model for underwater mine detection, a vehicle about 5 meters in length, is set to be introduced and scheduled to start operations in 2022.

The government intends to refer to further use of unmanned vehicles, which require no crew aboard, in the new National Defense Program Guidelines, as a way of establishing a policy of further adopting such vehicles.

In recent years, Chinese submarines have been very active in the East China Sea. As destroyers, submarines and anti-submarine patrol aircraft of the Maritime Self-Defense Force have been conducting warning and surveillance activities around the clock, it is said that there is a chronic shortage of crew members and ships.

“If we can use unmanned underwater vehicles at all times, our warning and surveillance capabilities will markedly increase,” a senior official of the ministry said.

On the other hand, the ruling Liberal Democratic Party and Komeito held a meeting of their working group on Friday, ahead of making decisions regarding the new National Defense Program Guidelines. Discussions were held on improvement of the Self-Defense Forces’ defense capabilities in “new areas,” such as in space and cyberspace or when confronted with the use of electromagnetic waves.

At the meeting, the government side explained to the ruling parties that it intends to include enabling the SDF to possess “cyber-counterattack capabilities,” enhancing their capability to interfere with an adversary’s electromagnetic waves, among other measures, in the new guidelines. Speech