Complex sentence: She sailed without incident, crossing the Atlantic during the peak months and cruising in the winter until 1927-with the advent of the new "Île de France", she was diverted almost totally to cruising.
Split into simpler sentences: She sailed without incident, crossing the Atlantic during the peak months and cruising in the winter until 1927. With the advent of the new "Île de France", "France" was diverted almost totally to cruising.