In 2018 local tourism operators and officials on Phi Phi island realised the numbers were unsustainable.

Maya Bay lies within a national park, and the Department of National Parks, Wildlife and Plant Conservation held a crisis meeting.

Despite concern from tourism businesses in the area, authorities successfully argued it should be shut down.

They argued that coral reefs were severely damaged and the ecosystem desperately needed time to recover.

On 1 June authorities imposed a demarcation line that boats could come up to but could not cross, and began patrolling the area so nobody could enter the bay precinct.

Dr Thon Thamrongnawasawat, a marine scientist from Kasetsart University who has studied Maya Bay and the area for 40 years, was hired by the ministry to survey the environmental damage and lead the rehabilitation.

"Back in 1998-1999, the damaged coral totalled about 30%, but now 90% of what’s there is damaged."

Coral reefs are fragile and very sensitive to water quality. Big crowds will always be detrimental to them because people tread on them and touch them.

But the big problem was the hundreds of boats, dropping anchor on them, leaking oil and scaring the fish.