Thousands of Chinese fishing boats have been massing in geometric formations in the East China Sea, in coordinated actions that experts believe are part of Beijing's preparations for a potential regional crisis or conflict. Monitoring ship-tracking data on Christmas Day, Jason Wang could tell something "unusual" was underway as fishing boats swarmed into two parallel inverted Ls,each about 400 kilometres (about 250 miles) long. Wang could see the roughly 2,000 fishing boats among the many thousands of vessels that ply the busy waterway through their automatic identification systems (AIS) -- a GPS-type signal that commercial ships use to avoid collisions.