In 1974 Matson Navigation Company took over Seatrain's West Coast-Hawaii service, leasing the "Transoneida", "Transchamplain" and "Transontario" to handle the traffic. In 1975 Navieras de Puerto Rico, also known as the Puerto Rico Maritime Shipping Authority, took over Seatrain's operations to and in Puerto Rico, along with the ships "Transhawaii", "Transidaho" and "Transoregon", which became Navieras' "Aguadilla", "Carolina", and "Mayaguez" (often confused with the Sea-Land Service ship of the same name involved in the Mayaguez incident). These two changes left Seatrain to concentrate on its international transatlantic and transpacific operations and replace its original converted container ships, mainly with a fleet of chartered ships, plus the new-builds "Seatrain Independence", "Seatrain Bennington", "Seatrain Chesapeake", "Seatrain Oriskany", "Seatrain Saratoga", and "Seatrain Yorktown".