 The expedition was to be resupplied with stores and provisions delivered by ships traveling up the Sea of Cortés, the commander of which would be Alarcón.Alarcón set sail from Acapulco with two ships, the "San Pedro" and the "Santa Catalina", on May 9, 1540, and was later joined by the "San Gabriel" at St. Jago de Buena Esperanza, in Colima.His orders from Mendoza were to await the arrival of Coronado's land expedition at a certain latitude along the coast.