Specifically, as the oil company informed, the PMB VI was a mooring boat which at the day of the incident was assisting the Pertamina tanker Enduro at a single-point mooring buoy eight miles off Belawan.
After completing the berthing, the mooring vessel was leaving the area when the bad weather caused high waves and winds. Thus, as Pertamina spokesperson Roby Hervino informed the local media, the boat struck Enduro's hull, capsized and sunk.
The accident resulted to the master's loss as he remained trapped in the vessel, whereas three crewmembers jumped over the side and were rescued. The crewmembers were transmitted to a naval hospital in Belawan.
CNN Indonesia reports that Hervino quoted
This was purely due to the weather, the ship was hit by the waves and sank.