In recent years, tens of thousands of young Africans have left the shores of Senegal and other West African countries in small boats headed for Spain's Canary Islands. Most have spent a week or more at sea, and unknown numbers have died in the attempt. Given the danger of the journey, we ask how it could become a large-scale social phenomenon. The analysis focuses on how prospective migrants assess and relate to the risks of migration. We show that risk taking is shaped by context-specific interaction of disparate factors. These include economic obstacles to reaching social adulthood, notions of masculinity, pride and honor, and religion, in the form of sufi Islam.