Dreaming of a new beginning, they come at night huddled in unlit motor boats lurching through the swells, trying to avoid the supertankers plowing through the Strait of Gibraltar--one of the world's busiest shipping channels.
Every night, dozens--often hundreds--of Africans make the treacherous crossing to Europe's southernmost tip in search of a better life in Madrid, Paris, Berlin and other points north.
For all those who make it, untold numbers perish in the turbulent waters of the channel that links the Atlantic Ocean to the Mediterranean Sea, spanning nine miles at its neck.
"The Strait of Gibraltar today constitutes the largest mass grave in Europe," said Santiago Yerga, a lawyer at a church-sponsored shelter in this port city who helps illegal immigrants get working papers.
Spanish authorities are struggling to cope with a spectacular rise in the number of illegal immigrants fleeing the poverty of their native lands.
In just one week in early July, 28 boats were caught bringing in an estimated 1,500 people. Police stations and unused army barracks along the coast were filled to capacity, but authorities admitted they were able to detain only about a third of the arrivals, allowing the rest to go under cover.
Enrique Fernandez Miranda, the head of Prime Minister Jose Maria Aznar's task force on immigration, has predicted that 20,000 people will be caught this year trying to sneak into Spain--nearly triple last year's figure.
Patrols have been stepped up and the government has all but sealed off the Spanish enclaves of Ceuta and Melilla on the North African coast, traditional staging points for the voyages.
A $102-million line of radar towers was supposed to be installed this summer to detect arriving boats. But it has been delayed after gaps in the coverage area were discovered during test runs.
Many doubt that technical know-how can quash the determination of people who have wagered all on finding a job in Europe.
After his father's death, Moulay Driss' mother sold everything of value to pay the $1,000 smugglers' charge for the passage so he could find work in Europe and send money to support his four younger brothers across the strait in Morocco.
But after his boat was intercepted at sea, the 22-year-old leaped from the fourth floor of a police station in an escape attempt, breaking both legs and fracturing his face in 15 places--"cleaving my skull like a melon."
"Look, here's the scar," he said, pushing back a shock of thick black hair to reveal an ear-to-ear line.
After weeks in intensive care, Driss was handed over to the Cardijn Foundation's shelter, where Yerga helped legalize his status.
Swelling with pride, Driss said in fluent Spanish that he wires money to his mother every month from his job as a parking lot attendant, but he hasn't told her of his injuries.
An indomitable spirit also pushed Louis Germain, who like most illegal immigrants agreed to discuss his situation only if his surname was not published.
After walking, hitchhiking and riding buses all the way from his hometown in Cameroon in central Africa, he paid a big fee to board a dinghy crammed with passengers.
"It's the kind of boat that back home we go fishing in," he said, speaking French. "When I got into the boat, I thought: 'If I die now, I die.' "
The Cardijn Foundation's network of five centers can take in up to 200 people a day.
New arrivals, who stay an average of a week before moving on, get fresh clothing, bus tickets to continue their journeys, and free advice on initiating the paperwork for temporary employment.
Despite their illegal status, Yerga defended the practice and said he achieves a 90% success rate, often finding loopholes in immigration laws.
"Not getting that little piece of paper after traveling thousands and thousands of kilometers means the catastrophe of a lifetime for these people," he said. "They're human beings. They deserve humane treatment."
Aznar's conservative government is ambivalent on the issue.
Unemployment is reaching double digits, especially in Spain's southern regions of Andalucia and Estremadura. But there is also a demand for unskilled laborers to do jobs now shunned by Spaniards--such as picking fruits and vegetables on farms that supply supermarkets around Europe.
"Spain needs and wants there to be immigrants," said Maria Angeles Morejon of the immigration task force. "But we want people to come with working contracts under their arms so they can have all the guarantees of legal labor and avoid exploitation. Our capacity for absorption is limited."
She said the government is negotiating repatriation procedures with the countries of origin that would allow an increase in the number of legal migrant workers.
Spain is not alone in its predicament. The long coastlines of fellow European Union members Italy and Greece are difficult to patrol and give illegal immigrants from the Middle East, Asia and Africa easy entry to Europe's southern flank. Once on land, illegal immigrants can travel around EU states without visas, thanks to the dismantling of border checkpoints.
The EU estimates it gets half a million illegal immigrants every year. They also cross from eastern Europe and arrive by air with temporary tourist visas despite efforts to step up controls and a rising tide of anti-foreigner sentiment.
Many Spaniards have a soft spot for the migrants, recalling that less than a generation ago, their own country was a major exporter of cheap labor.
Down the coast from Cadiz, in the whitewashed coastal village of Conil, an old, leathery-skinned fisherman pointed to the far end of the beach as he mended his nets under the blazing sun.
"I see them crying when the police come to get them and send them back," Jose Pareja Paricio said. "But how can you blame them for seeking a better life? They are God's children, like you and me."