A fleet of 30 boats, one of the largest in the history of Hainan province, returned on Sunday after finishing an 18-day fishing operation in the South China Sea.

The operation involved a 3,000-ton supply vessel, Qiong Sanya F8168, and 29 fishing boats. The 30 boats returned to a port in Sanya, Hainan, at 6:50 am, according to a statement from Hainan fishery authorities.

The fleet set sail for the fishing operation on July 12. The 30 boats reached waters near Yongshu Reef, Zhubi Reef and Meiji Reef in Nansha Islands and fished in those areas.

The operation was an ocean fishing trial in the South China Sea, and the fleet collected data of the exploration of fishing resources in the area, local fishery authorities said.

Fisherwoman Liang Yazhen is greeted by her granddaughter upon her return from a fishing voyage in the South China Sea on Sunday. Hou Jiansen / Xinhua

The operation lasted 18 days, and the voyage exceeded 3,268 km, the statement said. It was arranged by fishermen in Hainan voluntarily.

Eighteen of the 29 fishing boats belong to the Sanya Haiyu Fishers' Association, and 11 are from the Sanya Yufeng Fishers' Association.

"Nansha Islands have plenty of fishing resources. With the establishment of Sansha city and support from the government, we will go to the South China Sea for fishing more often," the operation's deputy commander, Liang Yapai, said on Sunday.

According to local fishery authorities, the operation marked the beginning of large oceangoing fishing. The province will gradually move from offshore fishing to oceangoing fishing.

The waters around Sansha have a potential fishery volume of 5 million metric tons every year. But currently Hainan has only 80,000 tons of fishing production, according to official figures.

On July 24, China established Sansha city to administer the archipelagos of Nansha, Xisha and Zhongsha. The new city also covers the islands' surrounding waters.

A military garrison has also been established in the city.

Contact the writers at jinhaixing@chinadaily.com.cn and huangyiming@chinadaily.com.cn