Its products have been deployed in 31 cities in 14 provinces and regions. Sales jumped from 3 million yuan, or 18 USVs, in 2013, to nearly 10 million yuan, or 50 USVs, last year.

Sales are forecast to surpass 20 million yuan this year.

Zhang expects the company will start exports this year, with talks going on with a number of potential agents. The company attended two foreign trade shows last year.

The company received Premier Li Keqiang and Russian Prime Minister Dmitry Medvedev at its booth during the third session of the Open Innovations Forum and Expo held in Moscow in October.

On the civilian side, USVs are mainly applicable in environmental protection, water resources, hydrology and ocean-related sectors, said Lyu Riheng, secretary-general of the technological development and commercialization committee of the Chinese Society for Oceanography.

The society plans to hold seminars on the use of USVs during its annual academic meeting later this year. These devices are scarcely used in the oceans surrounding China at present.

The situation is much the same in foreign countries, he said.

The products of Yunzhou, powered by lithium batteries, are equipped with technologies in the areas of global positioning systems, robotic control, automatic navigation, ultra-sound-based obstacle avoidance and wireless communications.

In combination with suitable devices, these products can be used to monitor nuclear radiation in water.

The company plans to launch a larger, faster, oceangoing model in the second half of next year. At present, this technology is available in just a few countries, including the United States and Israel.

Wu Yuyu and Wang Zijia contributed to this story.