Complex sentence: Fifteen years later in 1776, Bernard Boudin de Tromelin (from whom the island takes its name), captain of the French warship "La Dauphine", visited the island and rescued the survivors--seven women and an eight-month-old child.
Split into simpler sentences: Fifteen years later, in 1776, the French warship "La Dauphine", arrived at the island. They rescued the survivors--seven women and an eight-month-old child.