The 12-man vessel ran aground Tubbataha Reef, a Unesco World Heritage site, late on Monday.

BBC: China boat 'runs aground' Philippine Unesco coral reef

This same area near Greenville, which sees about 50 vessels pass on an average day, has been closed "intermittently" since August 12, when a vessel ran aground, said Tippets.

CNN: STORY HIGHLIGHTS

The rescue on Wednesday unfolded when the crew of the vessel, who left Canvey Island three hours earlier, rang 999 saying they had run aground but did not know where.

BBC: Coastguard plea after Canvey to Harwich voyage rescues

The oil drilling vessel, which has no engines of its own, was being towed for maintenance when it ran aground during a powerful storm on New Year's Eve.

NPR: Grounded Shell Oil-Drilling Ship Refloated