Inside Makoko: danger and ingenuity in the world's biggest floating slum

Makoko is the perfect nightmare for the Lagos government - a slum in full view, spread out beneath the most travelled bridge in west Africa's megalopolis. Yet this city on stilts, whose residents live under the constant threat of eviction, has much to teach

"One bucket, one life," says Ojo, puffing on a marijuana rollup. We have stopped by the Floating School, a two-storey solar-powered wooden structure that floats on the Lagos lagoon on a bed of plastic barrels. I ask him to explain what he means. It's the young fisherman's way of summing up the dangerous exertion that is his part-time vocation: sand dredging off the coast of Makoko, the world's biggest floating city.

The dredgers, he explains, descend a wooden ladder into the depths of the lagoon, armed with only a bucket and the will to live. The depths to which they go mean total submersion. Then they have to climb out with a sand-laden bucket that will be emptied on to the floor of a boat. When the boat is piled high with wet sand - high enough so that it's on the verge of sinking - it sails to shore, from where the sand is loaded on to trucks, for delivery to building sites around the city.