At about 6: 00 on September 14, 2012, two Chinese convoys including six maritime surveillance vessels arrived in the waters of Diaoyu Dao on a law enforcement patrol mission to uphold China's rights. These six vessels were numbered 50,15, 26, 27, 51 and 66. It's the first surveillance patrol task to be carried out after the Chinese government declared its official baselines of the territorial waters around Diaoyu Dao and its affiliated islands. The action aims to assert China's jurisdiction over the islands and safeguard China's maritime interests in the area.