Complex sentence: Underway from the harbor before 0900, for offshore patrol, "Ramsay" made sound contact with a submarine at 1120; released 10 depth charges; then watched an oil slick spread over the attack area.
Split into simpler sentences: Underway from the harbor before 0900, for offshore patrol, "Ramsay" made sound contact with a submarine at 1120. She released 10 depth charges, then watched an oil slick spread over the attack area.