BANGUI - On the banks of the Ubangi River, Odilon Salima and his co-worker sing to give themselves courage for the work ahead.
At dawn they are already out on the water, equipped with just a wooden dugout canoe and rudimentary tools.
It's not fish the muscular workers are after but another crucial commodity for the Central African Republic's economy.
Risking their lives and health, the so-called sandfishers dive deep into the murky depths to collect sand for the building industry.
Sometimes 36-year-old Salima says he dives as much as three metres (around 10 feet) deep to harvest a 35-kilo load.
The free divers must hold their breath while they plunge.
They work with paddles, spades and a crucial bucket, designed to retain just the sand.
"Under the water I have the bucket, which I must fill, and my colleague takes charge of loading the pirogue (canoe) with up to the requested quantity of sand," Salima said.
The sandfishers know the risks, but in one of the world's poorest countries, the work pays well and they have families to feed.
After decades of instability, renewed civil conflict broke out in the CAR after a violent takeover of power in 2013.
Although the fighting had lost intensity a few years later, bouts of violence by rebel groups or over resources still occur in rural areas.
For now, life in the capital Bangui remains relatively calm.
But making ends meet is a daily grind for most -- 71 percent of CAR's population lives on less than $2 a day, according to the World Bank.
Like elsewhere, sand is indispensable for construction. Mixed with cement, it is used to make concrete.
The country does not import sand and relies on digging it up from the Ubangi River and its tributaries in other towns, or from quarries.
And demand is strong.
Bangui, where Salima and his colleague ply their trade, has one million inhabitants and is constantly expanding.
With construction sites sprouting up all over, building firms pay 30,000 FCFA ($49, 45 euros) for eight cubic metres of sand from the Ubangi.
'LEAST OF OUR WORRIES'
"Every day we risk our lives in order to feed our families," father-of-two Salima sighed.
He has been sand diving for six years.
He earns 10,000 FCFA a day, the equivalent of around 15 euros, but half of that goes on renting the pirogue.
However, he makes more than most, as the average income for sandfishers is 7,000 FCFA for 12-hour working days.
"I save some (of my wage) to pay for the children's schooling, to care for my family," Salima said.
Even if life remains tough, he earns twice the average national income.
The United Nations estimates that in 2023 more than half of the population did not have enough to eat.
Some 56 percent depend on humanitarian aid in CAR, which is among the four least developed countries in the world.
Salima said he suffers hearing problems, headaches, issues with his back, lungs and breathing.
"But our health is the least of our worries," he said.
"With our expenses at home, there's almost nothing left to be able to see a good doctor and buy medicines."
Max-Benjamin Bagaza, a doctor at Bangui's general hospital, has seen the effects of diving on the few sandfishers who have come in for treatment.
"Dives with repetitive and intense movements can lead to joint injuries or muscle lesions," he said.
The risk of drowning also hangs over the divers and some do lose their lives, although no figures in this informal sector are available.
"Once, with the violent wind, the pirogue turned over... one of our colleagues, unfortunately, drowned," Salima said.
Most were unemployed before becoming divers, like 42-year-old Janet Botsilia who started sandfishing 10 years ago.
"We are in a country where finding work is almost impossible. It's worse for those of us who are without a diploma," he said.
Formerly a diver, he is now president of the Sandfishers' Association and owns 14 pirogues, which he rents out.
"It's thanks to this trade that all of us here -- including the young people working for me -- manage to support our families," he added.
Economist Didace Sabone said the sector must be made part of the formal economy in order to ensure divers' safety.
To do that, he said, would require equipment, heavy machinery and "lots of resources".