Scuba divers in George Town, Grand Cayman, were alarmed this week when they noticed a luxury cruise ship encroaching on a protected coral reef. The MV Zenith, a 700-foot ship with a carrying capacity of roughly 1,800 passengers, was “anchored oddly close to the reef,” said diver Scott Prodahl, in a YouTube video on Dec. 8.

Coral reefs, which are already in danger from climate change, are made up of tiny microorganisms that can take centuries to grow into their full splendor. Most of the world’s coral reefs are 5,000 to 10,000 years old.

Prodahl, an instructor at a nearby scuba diving outfitter, swam to the reef for a closer look, underwater video camera in hand. The footage he posted online shows the Zenith‘s anchor lodged ”well within the reef,” and the anchor chain “draped across the entire reef, constantly moving back and forth across the reef and causing a lot of damage as it did that.”

The footage was shot about an hour after the ship dropped its anchor, Prodahl wrote on YouTube. He also said:

The Department of Environment was contacted but nothing could be done because this was a designated anchorage zone and they were given permission to drop anchor. In the previous several decades this pristine portion of the reef was never needed as an anchorage location but for some reason today, when there was only 4 ships in port, it was deemed necessary. As part of the marine park, we are not allowed to fish here, not allowed to hunt lobsters, you can’t even pick up an empty shell, all in the name of conservation?….but for some reason you can drop an anchor and wipe out a reef that took thousands of years to grow.

The waters immediately offshore in the location Prodahl specified are part of a marine protected area, but according to the government’s marine park rules, anchoring is allowed within the zone—it just has to be approved by authorities.

The Zenith belongs to Pullmantur Cruises, Spain’s largest cruise line, which in turn is owned by Royal Caribbean. A spokeswoman for Pullmantur told Quartz via email:

When Pullmantur Zenith arrived to Grand Cayman on Tuesday, December 8, 2015, they were directed to a designated anchorage position. The spot where the ship dropped anchor was defined by local authorities and therefore it was correct, located in the zone designated by the government for anchorage, and was not in any protected areas. This is a very unfortunate situation and we are investigating closely with Grand Cayman authorities to clarify it. Grupo Pullmantur understands the importance of protecting the marine environment and sustaining the well-being of the places we visit. Protecting the health and welfare of our oceans is always foremost in our minds.

An official for the Grand Caymen department of environment told local news outlet Cayman Compass that ships had previously damaged the coral in the anchorage zone.

“We have reviewed the video footage and while it is not good to look at, the truth is that this site has been previously impacted. It hasn’t been subjected to the same amount of damage as the other anchorage sites, which is why you see surviving coral colonies there,” said deputy director Tim Austin.

Scuba divers and other marine life enthusiasts have railed against the ongoing destruction of coral reef habitat in the Cayman Islands, arguing that it is short-sighted to destroy a primary tourist attraction in order to transport more tourists to the islands.

This isn’t the first time a cruise ship was caught wrecking a reef with its anchor. A Carnival cruise line vessel did the same thing in 2014, in an area close to where the Zenith made its mark this week.

The image at the top of this post has been replaced. The image that was previously featured showed a specific ocean liner that is not associated with this story.