As dawn arrived off the coast of Senegal, navy commander Assane Seye scanned the horizon.
He is captain of the Niani, one of three new patrol vessels tasked with patrolling waters off the West African nation in search of a rapidly growing number of vulnerable boats carrying migrants on one of the world's deadliest migration routes.
Dozens of people pile onto the wooden fishing vessels known as pirogues and risk their lives on a journey toward Spain's Canary Islands , which have become the preferred landing point for West African migrants dreaming of a better life in Europe.
The Associated Press had rare access to one of the navy's night patrols.
At a glance, Seye and his colleagues can tell whether a boat is out for fishing or for migration. The number of people crammed on board is their clue.