Complex sentence: The African priests also believe that sometimes the Coco-de-Mer trees rose up above the ocean surface.Whenthis happened, the waves they created did not allow a ship that might be nearby to sail away, and then the helpless sailors were eaten by Garuda.
Split into simpler sentences: The African priests also believe that sometimes the Coco-de-Mer trees rose up above the ocean surface. When this happened, the waves the trees created did not allow a ship that might be nearby to sail away, and then the helpless sailors were eaten by Garuda.