PUERTO PRINCESA CITY, Palawan — Civilian boat Unaiza May 4 was dispatched to participate in the rotation and resupply of the troops aboard the BRP Sierra Madre at Ayungin Shoal in a trial mission to assess its potential for future use.

Western Command Chief Vice Admiral Alberto Carlos disclosed this to the media on Wednesday morning following the return of the UM4 to a military port in this city. Carlos was aboard the UM4 when two China Coast Guard (CCG) ships sprayed it with a high pressure water cannon on the morning of 5 March.

Carlos clarified that the indigenous vessel, embarking on its first journey to the West Philippine Sea (WPS), was not laden with supplies. Instead, the primary objective was to assess its ability to navigate to Ayungin.

The UM 4, being larger than the routinely deployed UM 1 and 2, warranted this evaluation.

Despite this being the UM4's inaugural voyage to the controversial shoal in Kalayaan town, situated in the West Philippine Sea, the indigenous boat had previously undertaken two "test missions" to Cuyo and Balabac municipalities.

"This is the secondary objective of our mission, to test the UM4, which is a lot bigger than the UM 1 and 2 we typically use. Since it is larger, its draft is deeper, so our concern is whether it can enter the shoal because the entrance is narrow and shallow," Carlos said.

"We intentionally didn't load it for the rotation. We sent it out primarily to test if it can enter Ayungin Shoal and come alongside the Sierra Madre," he added.

However, the test was thwarted as CCG ships obstructed the UM4 using dangerous maneuvers, which resulted in a minor impact, and shooting water cannons that damaged its glass windshields, CCTV cameras, and monitors, and injured four personnel.

For safety reasons, the Wescom chief said the UM4 had to return to mainland Palawan alongside its escort vessel, the BRP Sindangan.

Despite the obstruction, he said the RoRe mission on 5 March was successful, as the UM1 was able to enter Ayungin to deliver supplies and relieve the troops aboard the Sierra Madre.

"I'm happy to report that the RoRe was successful. At least, the primary mission to resupply and rotate the personnel—they are now aboard the UM1. Our secondary missions, unfortunately, due to illegal and coercive actions of China, we were not able to complete those, but the important thing is all personnel on the UM4 are safe, with only minor injuries," he said.

Carlos lauded the crew of UM4 for their adept maneuvering, evading multiple attempts by CCG ships and maritime militia vessels to block their path.

"But I have to give credit to the crew of UM4. For more than three hours, from 20 miles out, we were able to get as close as eight miles, covering 12 miles against the dangerous maneuvers of China," he said.

"Sometimes we were blocked, but then we managed to slip through. But the UM4 has limitations. Although larger, it is still very slow. As you can see in the video, even when the Chinese vessel reversed its direction, we couldn't outrun it, we would stop again and face another hole," he added.

Moreover, Carlos observed that China was more vigilant in monitoring the RoRe mission this time, possibly due to the involvement of a new vessel.

At 4 p.m. the previous day, they noticed they were being shadowed. A helicopter passed over them five times, with two instances of flying particularly close.

Initially, he said it seemed routine, given the normal presence of helicopters. However, upon closer inspection, the proximity seemed unusual. The helicopter circled for about an hour, indicating a serious effort to monitor the UM4.

This suggests they may have detected something out of the ordinary, he observed.

"And then the following morning, the cat-and-mouse game started at around 5 a.m. at 20 miles away from Ayungin Shoal," Carlos said, pointing out its unusual nature.

He also affirmed that despite the setback, they will make another attempt to get the UM4 inside Ayungin Shoal.

"We tried our best, we're going to do it again. We have to test whether this can enter the shoal because the UM1 is relatively small, so we would like to use this for future RoRes," he said.