The shores of Lake Victoria in western Kenya bustle with business - wooden fishing boats competing for space, carrying in the morning catch of tilapia, perch or catfish.
Under the scorching sun, the fishermen bargain with those queuing up to buy: mainly women, who hope to make a small profit at the local market.
But in this deeply poor part of Kenya, the transaction between fisherman and female market seller is rarely a financial one.
The currency is sex, not money: women selling their bodies in the hope of taking back a prize catch.
The practice is known colloquially as "sex for fish" - or, in the Luo language of the area, "jaboya".
Lucy Odhiambo, 35, prepares her latest purchase for the market, descaling the fish and slitting them open to remove their innards. A widow and mother of five, she says women here are in a bind.
"I'm forced to pay for the fish with sex because I have no other means," she tells the BBC.
"Usually I sleep with one or two fishermen a week. I could get diseases but I have no other choice: I have my children to send to school. Jaboya is an evil practice."
The "disease" is indeed widespread here - the HIV infection rate in this area is almost 15%, double the national average - and it is largely down to "sex for fish".
'No longer dependent on men'
But, slowly, the tide is turning.
Agnes Auma takes me out on the lake aboard a boat she now owns.
It is steered by fishermen she employs and when they catch the fish, she manages the sale.
Some of the money is paid to her staff, some is used to repay the cost of the boat - and the rest she keeps.
It is a project run by a local charity called Vired, supported by the US Peace Corps, and it is changing the lives of the women involved.
We talk as the boat winds its way past reeds and water hyacinth, the fishermen sweating as they navigate the narrow path.
"I saw I would have died, giving up my body for fish - and I couldn't continue," Ms Auma says.
"This project means I no longer have to depend on men to survive. I can fend for myself. And when I repay the money for the boat, I do it with a clean conscience."
As we reach the open lake, the net is unfurled for Ms Auma's catch.
A few minutes later, it is brought in: kilograms of silver cyprinid - the size of whitebait - glisten in the morning sun.
And then a large lungfish is brought up, slithering on to the boat as Ms Auma keeps watch.
"I'm very happy and proud of my fishermen and I'm very happy that I'm a strong fisher lady," she says with a smile.
To date, just 19 women are part of the project but Vired hopes it will gradually build.
"Sex for fish is very dangerous because every day we realise that people are dying from HIV and Aids," says Dan Abuto from the charity.
"We need to ignite these women, to empower them so they can take charge of their destiny. We are very proud because it's having a positive impact."
'I am ashamed'
But this is just one part of a country where "jaboya" is common.
And even here, there are plenty of fishermen still happy to accept payment in kind.
I meet one, Felix Ochieng, a 26-year-old who is married but still sleeps with three women a week in return for his fish.
He tells me sometimes a female customer will pay 500 Kenyan shillings ($6; £3.50) in cash and another 500 shillings with their body.
"I inherited this practice from my father, who used to do the same," he says, promising he uses a condom.
I ask if he is ashamed of what he does.
"Yes I am ashamed," he replies, staring out at the lake, "and it's a bad thing. But there are temptations that come with women."
Still some way to go then to eradicate a risky, long-entrenched practice.
But little by little, the numbers involved are falling and the women of Lake Victoria are understanding the dangers involved.
To end "sex for fish" for good, though, will require a change of mindset, for gender attitudes to be overturned.
And that will be far harder: a challenge to bring the purchase of fish here above board for good.