Thread by @GordianKnotRay

1/The preponderance of the evidence suggests that on 6 Feb #China Coast Guard ship 5205 stopped, harassed and followed #Philippines Coast Guard BRP Malapascua near Sabina Shoal for 8+ hours, preventing it from returning to Palawan. Let me explain my reasoning. [Thread 1/7]

2/BRP Malapascua (@coastguardph MRRV-4403) left Pag-Asa (Thitu) Island moving SE on 5 Feb/0930 PHT after anchoring overnight. Its companion for that night, BRP Teresa Magbanua (MRRV-9701), would move off to the NE 14 hours later. [2/7]

3/BRP Malapascua seemed headed to Palawan, but 3 hours after it left Pag-Asa CCG 5205 (marked "Unknown") left Mischief Reef moving west, came to a stop right across Malapascua's path & then at 1940L went "dark" (stopped transmitting its Automatic Identification System/AIS) [3/7]

4/Late that night at 06/0120L, east of Sabina Shoal BRP Malapascua turned sharply to port and slowed to 1 knot. It would remain essentially stopped for the next 11 hours. CCG 5205 remained dark on AIS for this entire period. [4/7]

5/Finally, just after noon BRP Malapascua got back underway but on a new course, this time due west. After slowing & taking a brief detour to the south, it again moved west toward Ayungin (2nd Thomas) Shoal, near where another China Coast Guard ship (5304) was on patrol. [5/7]

6/Just after midnight 7 Feb CCG 5205 at last reappeared back near Mischief Reef after Malapascua was well away to the north. (Notes: 5205 is marked "Unknown" but can be ID'd by its MMSI 512005205; the dashed line indicates when its AIS was off & its exact position unknown.) [6/7]

7/Until CCG 5205 reappeared at Mischief Reef I hesitated to voice my theory directly. Now I think the preponderance of evidence I have suggests it had a protracted confrontation with BRP Malapascua, which looks to be rejoining BRP Teresa Magbanua north of Jackson Atoll. [7/7 END]

Addendum: The time between when BRP Malapascua first turned and stopped near Sabina Shoal (0120L) to when it turned away from Ayungin (2nd Thomas) Shoal (1920L) was ~18 hours. Upon reflection it seems probable CCG 5205 remained in close contact for that entire period.