Oscar W was built 1908 in Echuca by Charlie Wallin and named for his son Oscar. The paddle-steamer was just over 103 feet long, with a beam of 20 feet and a draught of between 2 to 5 feet depending on loading. It was a composite construction, with steel topsides, and red gum below and powered by a 16hp wood burning 2 cylinder engine. In 1914 Wallin sold the Oscar W to Permewan Wright and Company and until 1919 it was engaged in the wool trade, continuing to operate on the upper river system. Murray Shipping Ltd was formed out of the amalgamation of several companies and the new company kept the Oscar W in the wool trade on the Darling River, but also as a supply vessel for the construction of the lock system. By 1943 the Oscar W was in the hands of the South Australian Highways Department and being used for ferry maintenance work. Her boiler was changed in 1945 to oil burning. Sold again in 1959 the paddle-steamer was employed by her new owners in the tourist trade.

After a further sale and a conversion back to wood burning, Oscar W was sold to the South Australian Tourism Department in 1985 and extensive repair work was carried out: the paddle-steamer's new life would be as the flagship for the Signal Point River Murray Interpretive Centre at Goolwa. Finally in 2001 the Alexandrina Council took over the ownership of the Oscar W and the barge Dart and they were used in historical and community celebrations on the lower river and lakes. The vessel's centenary was celebrated in October 2008.

The paddle-steamer Oscar W with its barge Ada still holds the record for the largest cargo of wool bales brought down the Darling River: 2, 208 bales.