China and Vietnam conducted a joint mission in the Beibu Gulf between Vietnam and China's Hainan Island from August 18 to August 20 to patrol fishing waters in the two counties' "common fishery zone".

China Yuzheng 311, the country's largest fishery administration vessel, and China Yuzheng 45001 took part in the 231-nautical mile-long joint patrol along with two ships from Vietnam's Marine Police.

This is the fourth joint patrol of its kind held by China and Vietnam since 2006.

The common fishery zone, which includes parts of China and Vietnam's exclusive economic zones in the Beibu gulf, was defined by two pacts signed in 2000 that took effect in 2004. Fishing boats with a certain license from China and Vietnam's fishing authorities are allowed to fish in the zone for free.

Because the fishery cooperation pact sets maximum limits on the amount the two countries' fishing boats can fish, fishermen usually draw lots to determine who gets the license.

During the patrol, Chinese fishery administration officers and Vietnam's marine policemen boarded Chinese and Vietnamese fishing vessels to make sure they were operating legally, and that they did not use any illegal fishing methods, such as electric nets. According to a Chinese fishery administration officer Liu Jia, no violations were found.

Notably, for the first time, commanders of the two countries' fleets made courtesy calls to each other's ships during the voyage. Liu Tianrong, deputy director of the Administration of Fishery Supervision of the South China Sea, said the joint patrol is a good way for the two countries to jointly administer the fishing zone. An exchange visit to each other's ports might be possible on the next patrol as well, Liu said.

"Now the two countries' fishing authorities will provide help for Chinese and Vietnam fishermen in the area when they have troubles," Liu said.