Swarming is a commonly used tactic involving dispatching a flotilla (often a combination of militia, coast guard, and sometimes navy vessels) to overwhelm and intimidate other countries' assets, assert dominance, or provide a security screen for certain Chinese ships on special missions. 

Examples: 

Starting on May 7, 2023, Chinese survey ship Xiang Yang Hong 10 and a flotilla of escort vessels consisting of China Coast Guard (CCG) and Maritime Militia (PAFMM) vessels spent nearly a month conducting survey operations deep within Vietnam's Exclusive Economic Zone (EEZ). These activities led to a formal protest from the Vietnamese government. 

On March 4, 2023, one People’s Liberation Army Navy (PLAN) ship, one CCG ship and 42 PAFMM vessels gathered near Thitu Island. Thitu Island (also known as Pag-Asa) is home to one of the Philippines' most important military outposts in the West Philippine Sea, as well as a small civilian population. 

On July 22, 2014, a Vietnamese fishing boat was surrounded by Chinese vessels 5 nautical miles South of Collins Reef. Chinese coast guard ships then rammed the fishing boat, which nearly sank.

On June 29, 2014, 45 nautical miles to the southwest of Paracel Islands, about 34 Chinese fishing vessels, supported by 2 coast guard ships, closely followed, obstructed and intimidated Vietnamese fishing vessels operating in the area.

See the rest of the playbook here.