GUANGZHOU - Chinese marine authorities on Sunday added a new ship to the fleet patrolling South China Sea.

The 1,500-ton-class vessel, 88 meters long and 12 meters wide, was enlisted as the thirteenth patrolling ship of the South Sea fleet of the China Maritime Surveillance Force in the southern city of Guangzhou.

The ship will mainly be used to "protect the country's maritime interests, enforce maritime and environmental laws, " officials said, adding that the ship, equipped with sound waves detector and analyzer, can also be used to conduct scientific research.

The South Sea fleet now has 13 patrolling ships, two planes and one helicopter.

China has a coastline of 32,000 km and 350,000 square km of territorial seawaters and internal waters. It also has 3 million square km of its exclusive economic zone as recognized under the United Nations Convention on the Law of the Sea.

China's Ocean Development Report 2010 released last May said the country's maritime rights and interests faced complicated situations and safety threats which include sovereignty over islands, sea delimitation, sea resources disputes and terrorism.