Complex sentence: Between 1916 and when the bridge opened in 1930 the Mosquito Fleet ferry "Pioneer" serviced the crossing between Bremerton and Manette for most of the time; sometimes the "Urania", a passenger only ferry, filled in.
Split into simpler sentences: Between 1916 and when the bridge opened in 1930, the Mosquito Fleet ferry "Pioneer" serviced the crossing between Bremerton and Manette for most of the time. Sometimes the "Urania", a passenger-only ferry, filled in.