"Rafting" refers to the gray zone tactic of tying ships together at anchor to establish semi-persistent floating outposts that are difficult to disperse due to their collective mass. 

The ships are generally the component of China's People's Armed Forces Maritime Militia (PAFMM) known as Spratly Backbone Fishing Vessels (SBFV). According to the Asia Maritime Transparency Initiative's detailed report on the PAFMM, these SBFVs receive generous government subsidies to remain at sea for most of the year, specifically to assert Beijing's expansive maritime claims.

As indicated by SeaLight Director Ray Powell in an interview with Channel News Asia, this gray zone tactic enables the PAFMM to effectively occupy features without the cost of new construction activity, while also being able to claim that the presence of its ships is both legal and unremarkable.

Examples: 

On June 30, 2023, the Philippine government reported spotting as many as 48 Chinese fishing vessels rafting at Iroquois Reef, with three China Coast Guard ships and two naval vessels loitering at nearby Sabina Shoal. 

Chinese fishing vessels in the Philippine EEZ, June 30 2023 (Source: Philippine Coast Guard Photo)

Between March 2021 and June 2021, more than 200 Chinese marine vessels rafted together in groups to form temporary floating outposts in Whitsun Reef, a boomerang-shaped coral bar about 175 nautical miles west of the Philippine province of Palawan—which puts it within the Philippines' 200 nautical mile exclusive economic zone, or EEZ. 

While China claimed that the vessels were “merely fishing trawlers taking shelter from storms”, the continued presence of rafted ships to the present day undermines this justification. 

PAFMM vessels rafting at Whitsun Reef, March 23, 2021 (Source: Asia Maritime Transparency Initiative, Maxar Technologies)

See the rest of the playbook here.