In September 1946 a new ship, the S.S. "Norisle"—the name being derived from "North (Manitoulin) Island"—was put in service on the ferry route. Designed and built by the Collingwood Shipyards Limited for OSTC, the "Norisle" had a capacity of up to 50 automobiles and 250 passengers. Having more than twice the capacity of the S.S. "Caribou" and M.S. "Normac" combined, it was expected this new ship could handle the Tobermory - South Baymouth auto ferry route alone; however, because of an unanticipated increase in the volume of car traffic after the war, the "Normac" continued in service with the "Norisle". Like her predecessors the "Norisle" was also equipped with staterooms for the accommodation of up to 100 passengers, enabling her to be used also on the Owen Sound - Sault Ste. Marie route during early and late navigation seasons.