The alleged incident happened in 2014 during a crossing from Morocco to Spain.
Alain N. B. was the captain of the inflatable boat. Survivors of the journey claim that he blamed a storm they encountered on "the prayers led by a Catholic pastor" and forced Christians off the boat.
Around 29 sub-Saharan migrants out of 50 survived the trip.
They said the captian and his second in command, who died before the trial started, thought that "the weather worsened every time the victims prayed."
Witnesses claim the pair used wooden planks on the boat to beat a pastor from Nigeria.
The men then allegedly searched passengers for Christian symbols under their clothing and attacked a further five people.
The trial continues.
