A helicopter rescue teamtakes part in a lifesaving exercise on Thursday. [Photo/Xinhua]

Range of recently constructed navigation aids in South China Sea helps all vessels

China is perfecting maritime navigation aids for civilian vessels in the South China Sea, as the country has built two lighthouses and four beacons on the Xisha Islands, sources told China Daily.

In addition to the visible aids - lighthouses, beacons and buoys - China is also offering radio aids to support navigation, such as the Automatic Identification System, a tool used around the world for marine contacts.

As of May, China had four base stations for AIS communications on the Xisha Islands, providing complete coverage of the area, insiders familiar with China's navigation safety services and relevant buildups said on the condition of anonymity.

Now, with a click on the client app on a cellphone, one can see the locations of vessels sailing in the Xisha area, including basic identifying information and destination.

"The AIS service helps navigation in extreme weather conditions, including typhoons, and is critically important for avoiding collisions. Unlike cars, ships cannot make a sharp U-turn," one of several sources said.

China's lighthouses have also been flashing in some parts of the Nansha Islands, including Huayang Reef, Chigua Reef and Zhubi Reef.

The sources said the lighthouses have multiple functions, hosting base stations for services such as AIS, VHF and civilian cellphone networks, "making them a comprehensive platform".

Before the navigation aids came along, some island dwellers put red caution lights on their rooftops to help ships find their way late at night, when nothing else could be seen in the darkness.