After receiving blessings from Buddhist monks, they lower their masks and plunge one-by-one into the mighty Rangoon River, clinging to garden hoses that will act as primitive breathing devices during their dizzying descent into darkness.
From the shoreline, thousands of spectators look on, some peering through binoculars, praying the men will find what other salvage crews have not: the world’s largest copper bell, believed to have been lying deep beneath the riverbed for more than four centuries.
Weighing an estimated 270 tons, the mysterious bell is a symbol of pride for many in a nation of 60 million that only recently emerged from a half-century of military rule and self-imposed isolation.
And for the first time, search crews are largely relying on spirituality rather than science to try to find it.
Burma’s superstitious leaders have in years past been part of a colourful cast of characters who believe reclaiming the treasure is important if the nation is ever to regain its position of glory as the crown jewel of Asia.
It is a story of myth and mystery. King Dhammazedi, after whom the bell was named, was said to have ordered it cast in the late 15th century, donating it soon after to the Shwedagon Pagoda, Burma’s most sacred temple which sits on a hilltop in the old capital, Rangoon. The bell remained there for more than 130 years, when it was said to have been stolen by Portuguese mercenary Philip de Brito, who wanted to take it across the river so it could be melted down and turned into cannons for his ships.
With tremendous difficulty, his men rolled the massive bell down a hill and transferred it to a rickety vessel, which then sank under the weight.
Most people in Burma believe the bell is still lying deep beneath the riverbed, buried under layers of silt.
But numerous efforts to locate it with the help of sonar imaging and other hi-tech equipment have failed, and some historians now question whether it even exists.
The latest operation – which is expected to last up to 45 days and cost £150,000 raised through donations – is being headed by a former naval official, San Lin, who believes the copper treasure is protected by a curse.
When he announced at a press conference in July that he was one of the reincarnations of the 14 guardians of the bell and could speak to the spirits of those who have blocked past retrieval efforts, many local reporters laughed, ignoring the story altogether.
But accounts of the recovery efforts have since captured imaginations – the prayers, the offerings to “nats,” or spirits, the vegetarian diets adopted by the diving team in deference to Buddhist principles.
Now, unsubstantiated rumours that the bell has been spotted have sent thousands of curious spectators flocking to the Rangoon River’s banks.
For small-boat owners, shuttling passengers to within a few metres of the divers’ boats has become a brisk business, with dozens of wooden, canoe-like vessels lining the banks.
On shore, men and women charge 200 kyat (12p) for photocopied pamphlets describing the bell and its history. Food and drink stalls have popped up.
“We came because, as Buddhist people, we are responsible to pray for the bell to get it back to its original place,” said Tin May, 43, dressed in a traditional longyi, or sarong, and a white blouse. “I don’t live far from here. But I keep getting calls from relatives living in the countryside asking for the latest news. Finally, I decided I better get a firsthand look.”
Chit San Win, a historian who has taken part in several searches in the past two decades, is having doubts. Three historical records written about that period do not mention the bell, Win said, and King Dhammazedi, who recorded all his donations, did not document gifting a bell that would have weighed more than 100 Asian elephants. The only record Win found that mentions the bell was written by an Italian merchant, Gasparo Balbi, who came to Burma in the 16th century and wrote that he saw it. And the supernatural search technique? “The bell cannot be located with the help of astrology or spirits,” Win said. “It is just like consulting an astrologer to find a lost cow who would ask you to look for it in all four directions.”