According to the Vietnam Fisheries Surveillance Department, on the day, China deployed two aircraft, including a helicopter, flying above the rig site.

Vietnam fisheries surveillance vessels maintained their presence about 10-11 nautical miles from the rig to demand China withdraw the facility and all ships out of the waters of Vietnam.
 

However, they were hindered by lines of Chinese ships of various kinds and their bullying sirens. 

Meanwhile, Vietnamese fishing boats, with the assistance from fisheries surveillance vessels, continued to stay at their traditional fishing grounds at a distance of 42-45 nautical miles from the rig.

In the area, they were often circled by about 30 Chinese fishing ships, supported by a coast guard ship and a fisheries surveillance ship, which tried to disrupt their operations and drive them away.

At the beginning of May 2014, China illegally dispatched the rig as well as a large fleet of armed vessels, military ships and aircraft to Vietnam’s waters and positioned the rig at 15 degrees 29 minutes 58 seconds north latitude and 111 degrees 12 minutes 06 seconds east longitude. The location is 80 miles deep into Vietnam’s continental shelf and exclusive economic zone. 

Despite Vietnam’s protest, China expanded its scale of operation and moved the rig to 15 degrees 33 minutes 36 seconds north latitude and 111 degrees 34 minutes 11 seconds east longitude, 60 nautical miles deep inside Vietnam’s continental shelf and exclusive economic zone. 

China’s armed vessels have aggressively and consistently fired high-power water cannons at and intentionally rammed against Vietnamese public-service and civil ships, causing damage to many boats and injuring many people on board. 

On May 26, Chinese ship 11209 even sank a Vietnamese fishing vessel that was operating normally in its traditional fishing grounds near Vietnam’s Hoang Sa (Paracel) archipelago.