The past year has seen a huge effort by Beijing to exclude Philippine government vessels from Scarborough Shoal. Scenes like the one displayed below have become commonplace, with aggressive patrolling and blocking by the China Coast Guard (CCG) and militia ships routinely keeping Philippine Coast Guard (PCG) and Bureau of Fisheries and Aquatic Resource (BFAR) vessels 25 nautical miles or more from the shoal:

This is a new development, as over the past 12 months SeaLight's ship tracking has observed more than double the number of individual CCG and militia automatic information system (AIS) broadcasts around the shoal than over the previous period. While there's no perfect way to measure time patrolling around a given feature, the number of individual AIS broadcasts can give us a general idea of the scale of activity.

SeaLight's Anna van Amerongen produced visualizations using this data to show heat maps of both years in sequence. We tracked 57 CCG and militia ships producing around 724,000 total AIS broadcasts near Scarborough Shoal from May 2023 - April 2024. The result was a relatively tight area of focused activity very near the shoal:

Over the following 12 months, by contrast, we see the area of intense activity expanded dramatically, with 78 ships and 1,573,000 broadcasts--or more than double the total signals broadcast over the previous period. We also see China's ships ranging in all directions, but especially to the east toward the Philippine mainland:

Measured another way--by observing the number of CCG and militia ships around the shoal on just the first day of each month--we can clearly see how China's patrols around Scarborough Shoal trended have upward over the two year period, even as it began to introduce dangerous maneuvers around Philippine ships and aircraft over the 13 months.

So what was the Philippines doing in response to all this increased aggression? In short, pushing as hard as its means allowed against a vastly larger force. Philippine AIS returns in the first period was a modest seven different PCG and BFAR vessels producing 55,000 AIS broadcasts around the shoal, even as these ships were routinely able to approach very near the shoal itself.

As China increased its patrols over the following year, so did the Philippines. We observed 11 different ships producing 217,000 AIS broadcasts--a nearly fourfold increase--in that period. Despite this, the Philippine government vessels' ability to reach the shoal itself appears to be over, at least for now:

China has been working hard to create new "facts on the ground", with its newly declared baselines and what amounts to a blockading force around the shoal. The Philippines continues to do what it can to support its fishermen and signal its unwillingness to yield its claim, but it clearly faces a long, uphill battle.