At about 6: 00 on September 14, 2012, two Chinese convoys including six maritime surveillance vessels arrived in the waters of Diaoyu Islands 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 Island and its affiliated islets. The action aims to assert China's jurisdiction over the islands and safeguard China's maritime interests in the area.