Any diver who’s experienced Raja Ampat’s Dampier Strait had to feel at least a little ill when they heard the news: A British cruise ship on a bird-watching expedition rammed reefs in the famed strait, off Indonesia’s Waigeo Island, early this month.

The strait is beloved in the dive world as a living highway of all things pelagic — especially mantas (shown in video below), which can reliably be experienced at Dampier sites from Blue Magic to Manta Sandy. The sheer volume of life passing through the strait north of Sorong, West Papua — departure point for many liveaboards plying Raja Ampat’s waters — is so staggering it’s actually audible, in what’s locally called “fish thunder.”

The 300-foot Caledonian Sky, a Bahamian-flagged vessel owned by tour operator Noble Caledonia, ran across reefs at low tide after a tour on Waigeo Island March 4.

Rescue efforts may have made matters even worse, according to a member of the local team evaluating the incident.

“A tugboat from Sorong was deployed to help refloat the cruise ship, which is something that shouldn’t have happened because it damaged the reef even worse,” Ricardo Tapilatu, head of the Research Center for Pacific Marine Resources at the University of Papua, told Britain’s Guardian newspaper. “They should’ve waited for high tide” to refloat the vessel, he said. Nearly 2,000 square yards of coral was destroyed. The evaluation team is expected to recommend the cruise operator pay compensation of between $1.28 million and $1.92 million, Tapilatu told the Guardian, which would be used for reef restoration as well as prevention measures. Restoration efforts could take a decade or more.

Damage to the ship was minimal; the cruise operator, which described the destruction as “unfortunate,” says it is cooperating with Indonesian authorities.

Local diving instructor Ruben Sauyai was in tears after seeing the ruined reef. “The damage is huge and acute. It could take 10 to 100 years to repair it," he told the BBC.