In early January, 2013 China commissioned a new 4,000 ton patrol ship for its Coast Guard. While not carrying much in the way of weapons, it has surface and air search radars, a helicopter, boarding craft and space for several hundred people. These could be victims of some maritime disaster, or troops for some emergency in the South China Sea.
These new large patrol ships have top speed of 36 kilometers an hour and supplies (food, fuel) to stay at sea for at least three weeks at a time. These ships have a desalination system to supply their own water at sea and an all-electric drive and a propulsion system designed to give the ship high maneuverability and the ability to maintain position in rough weather.
China is building several dozen of these larger patrol ships, ranging size from 1,500 tons to 12,000 tons. All appear to be in support of the Chinese assertion that their “coastal waters” extend more than a thousand kilometers from the Chinese mainland.