The St David and St Patrick were ere sister ships built by Cammell Laird and Company of Birkenhead in 1947. St David was 3,352 tons and St Parrick 3,482 tons, both 321 feet in length and 48 feet beam, twin screw steam turbine engines, each vessel carrying 1,300 passengers and 50 cars. Their normal route was Fishguard-Rosslare, but from 1948 to 1963 St Patrick was used quite frequently as a relief vessel on Channel Island services.
St David first came to Jersey late in 1947 to trial the route before the introduction of St Patrick the following February. The third steamer to bear the name, St Patrick was not owned by British Railways, but by Fishguard and Rosslare Railways and Harbours. She operated from Weymouth for several summers, and was officially transferred to BR in 1959 following the reorganisation of Channel Island services. She operated mainly at weekends as back-up for the Caesarea and Sarnia which commenced operations in 1960.
Following the withdrawl of Brittany, St Patrick was also used on the Jersey-St Malo run, and as a larger and more modern vessel she proved popular, until the route was closed on 27 September 1964.
After this St Patrick was only occasionally seen in island waters operating excursions and charters before being sold to Greece in 1972.
St Patrick passing Elizabeth Castle in 1948