Complex sentence: Her crew survived by clinging to her mastheads, which remained above water after she sank in 20 feet (6.1 meters) of water, and managed to free one of her boats about an hour after she sank and row to shore safely.
Split into simpler sentences: Her crew survived by clinging to her mastheads, which remained above water after she sank in 20 feet (6.1 meters) of water. The crew managed to free one of her boats about an hour after she sank and row to shore safely.