In 1977 the operation had outgrown its base in Easton and moved to Southern National's former garage in Victoria Square, Portland.  As mentioned above, Smiths came back into the bus business in 1981 with three return journeys a day between Weymouth and Portland.  In 1982 this became ten journeys and in 1988 this had grown to sixteen return journeys a day.  The business was incorporated as Smiths of Portland Ltd in 1983.  Douglas Smith retired in 1987 and was followed in the business in turn by his son Rodney.  By now Weybus were also competing on Weymouth area routes - indeed competition between the three operators was fierce and sometimes aggressive.

Early in 1989 the Smith family sold the business to neighbouring Portland Plant Ltd who in turn sold the business in summer 1989 to the Cawlett group, who now owned Southern National.  A co-ordinated timetable was operated with former rivals Southern National.  Cawlett sold off the Smith business in 1994 to a Plymouth businessman called Rimmer.  With Weybus coming onto the Portland route with a fifteen minute frequency in 1995, Smiths introduced a joint timetable with Southern National to Portland and responded further with a competing half hourly service from Weymouth to Littlemoor Estate. In April 1996 this new service was extended westwards from Weymouth town centre to Hereford Road, creating further competition, and leading to progressive fare reductions as all three operators vied for trade.   

Such a situation could not continue indefinitely, and from June 1996 the Traffic Commissioner banned Southern National from the Portland route - which was immediately and somewhat cheekily registered by their sister company Dorset Transit!  So still three operators in competition on the Portland service.  In the autumn of 1996 Smiths withdrew from Littlemoor and then in December from Hereford Road.  Vehicles used included Bristol REs until 1996, and then some Freight Rover Sherpa/Carlyles and also some Dormobile/Ivecos.  In September 1997 more arrived from Cityline Bristol and ran for two years.

In January 1998 the Smiths business was repurchased by the Cawlett group and in July the Weybus services ceased to operate when their licences were revoked by the Traffic Commissioner.  So Cawlett had Portland to themselves again, albeit with two operations: Dorset Transit and Smiths.  April 1999 saw Cawlett acquired by the First group, and Smiths ceased to trade separately in September 1999, all services then coming under the First Southern National banner.