Underwater Drones Big Hits for Business, Research, Rescue in Japan

The Yomiuri Shimbun
Takami Yasuoka, president of Yasutaka Suisan, puts an underwater drone into an aquaculture pond to inspect it in Ainan, Ehime Prefecture.
The Yomiuri Shimbun

MATSUYAMA — Much like their aerial counterparts, the technological development of underwater drones has expanded their usefulness in a wide range of activities. These submersibles are proving valuable in the fisheries industry, ocean research and marine rescue, especially as their diving and camera capabilities are improved.

The government has started to help promote the use of this technology, claiming that it will lead to regional revitalization and the development of new industries in Japan.

Improving safety

Yasutaka Suisan, a fisheries company in Ainan, Ehime Prefecture, operates submersible drones in its aquaculture ponds floating in the sea. The drones are able to report the underwater situation back to a computer screen, such as swimming behavior of red sea bream and net conditions, and can dive to a depth of nearly 100 meters to check the pond’s clamps on the seabed.

The company had been relying on weekly inspections from outside divers. However, because the fishery has 114 of these floating ponds, which are 20 meters deep, checking every centimeter was extremely difficult. And after bad weather, the risk of accidents was high.

Since the company gradually introduced four underwater drones starting four years ago, the work has become more efficient. The new technology has an advantage of being able to quickly notice any changes in the fish, according to the company.

“Aquaculture used to be hard work and relied heavily on experience,” company president Takami Yasuoka said. “With the latest technology transforming our industry into a safe one, we can expect the participation of people who have never been involved in this kind of work before.”

Underwater drones have been introduced in Matsue, Shimane Prefecture, and Susaki, Kochi Prefecture, for the inspection of fixed nets and other purposes. An experiment has begun in Etajima, Hiroshima Prefecture, to test the use of underwater drones for monitoring the growth environment of cultivated oysters.

Underwater drones have been getting better in recent years, and their prices have been coming down. A small drone — weighing 2 to 3 kilograms and the size of a laptop computer — that can dive to a depth of 100 meters is now available for ¥150,000 to ¥200,000.

According to estimates by the research firm Impress, the size of the domestic market for industrial underwater drones is currently estimated at about ¥2 billion, and expected to nearly double in three years.

“Like aerial drones, they have great potential in a variety of fields,” said an official at the Japan Underwater Drone Association.

The Enoshima Aquarium in Kanagawa Prefecture began using drones to survey the biology of Sagami Bay in October 2019. Last summer, the facility collected a rare harp comb jelly from the seabed at a depth of 130 meters, the first time in 79 years in the area. An official in charge of the project said that more valuable discoveries and collections can be expected in the future.

The Niihama City Fire Department in Ehime Prefecture introduced underwater drones in 2019 in response to a series of accidents in which cars fell into the sea. In addition to assessing the situation in the event of an accident, drones will also be used to provide guidance to diving crews.

In November, an experiment was conducted at the Odo Dam in Niyodogawa, Kochi Prefecture, using underwater drones to measure the condition of the dam and repair points. The experiment was conducted by the Land, Infrastructure, Transport and Tourism Ministry’s Shikoku Regional Development Bureau. The drone was able to identify areas in need of repair with only a small margin of error, and the bureau will make efforts to put the drone technology to practical use.

Regional revitalization

In coastal areas and remote islands, the aging of the population and the deterioration of port facilities are serious problems, as there is a shortage of people who can take on dangerous diving work.

In November, the government set up a council to study the use of underwater drones and other equipment with the participation of industry, government, and academia.

In addition to making up for the shortage of manpower in industry and inspection work, the following areas of potential use were mentioned: producing underwater virtual reality videos to attract diving tourists; surveying underwater ruins, resources and organisms; educating marine engineers; and confirming tsunami damage.

The Ocean Policy Division of the land ministry said that the use of drones will lead to the revitalization of coastal areas.

While the aviation law and other regulations prohibit flying drones without permission in dense residential areas, there are few regulations on the use of drones at sea. The challenge is to create rules to prevent accidents.