Between 750,000 and one million African migrants are waiting today on the Libyan coast for their chance to try lampa-lampa. This word, presumably derived from Lampedusa, a tiny Italian island between Tunis and Malta, is slang for the Mediterranean crossing. And these numbers don’t take into account those who set out from Tunisia and Morocco.

Award-winning BBC journalist Paul Kenyon befriended Justice Amin while making a two-part documentary on African migrants a couple of years ago. This is the story of how Justice travelled from Effiakuma, a small town in Ghana, to Libya, to Italy.

Ibrahim, Justice’s abusive uncle, refused to allow him to go to school at the local Methodist mission. So the boy tried to pick up scraps of knowledge in other ways. He studied the Koran hard and was fascinated by its many similarities with the Old Testament, particularly the story of Jonah’s punishment and his three days in the sea-monster.

Western TV reports of migrants arriving in flimsy boats, dehydrated, disheveled and completely distraught, highlight the fact that they survived a Mediterranean crossing. They also survived crossing the Sahara. Most migrants arriving in Italy are from sub-Saharan Africa, many of them from hundreds of miles south of where the Sahara begins -- from Ivory Coast, Nigeria, Cameroon, Ghana, Congo and Central African Republic. Only the young, the ambitious and the able-bodied set out, knowing well that they may never see their families again. They board rickety buses carrying oodles of optimism, a few belongings and a little cash. They earn their passage on the way, odd-jobbing and relying on the modest hospitality of strangers.

Agadez, a town of 50,000 in Niger, where the Sahara begins, is where migrants meet to proceed north across the forbidding sea of sand. Desiccated corpses of those who were beaten by sand and lack of water strew their path.

Before leaving Accra, where with his meagre education, he would never earn more than a pittance, Justice tried his hand at wall-painting, working on a building site, as market-porter, tea-maker and tailor. But his mind was set on greater things, Britain, the land of his favourite soccer stars and well-paid work.

With youth and resilience, men like Justice, who was 17 when he set out, can handle natural obstacles. The human ones are much more challenging. The moment they cross the Libyan border from Algeria they were arrested and locked up. They managed to escape by taking advantage of their guards’ drinking binge. In February 2006, Justice reached Tripoli, on the Libyan coast. His first task was to find fellow-Ghanaians and someone to arrange the trip. He earned money by skinning goats.

A migrant like Justice is full of fear: of being deported from Libya and sent home across the desert; of paying cheats who leave you stranded or murder you; of surviving the crossing. People-smuggling is very lucrative, especially during the warmer months when the sea is calm. The 27 in Justice’s boat would earn the smugglers more in one night than the average Libyan takes home in a year.

The passengers are packed like sardines and exposed to sun and rain for at least 300 miles of open sea. No one in Justice’s boat knew how to swim. All but one, a silent boy, were believers, Christian or Muslim, and prayer and fasting came easily. When the boat filled with water, they asked if the silent boy was their Jonah, the cause of their misfortune.

But by some good fortune, they did not drown. They were rescued from their sinking boat by an Italian warship whose captain and crew looked after them well.

What happens to these boat-people? Few of them fulfill their dreams. Justice wandered from job to job, from town to town, every time about to break through but never quite making it.

The annual migration of the wildebeest in the Masai Mara game reserve in Kenya has been hailed as one of the wonders of the world. But this human migration across deserts and stormy seas is even more remarkable. What a shame that energetic, intelligent, hard-working, ambitious young men have to risk their lives to be able to send back money to their families, all because of corruption and poverty at home.

Martyn Drakard writes from Kampala, in Uganda.