Shamrock was a racing yacht built in 1898 that was the unsuccessful Irish challenger for the 1899 America’s Cup against the United States defender, Columbia. Shamrock (also known as Shamrock I, to distinguish her from her successors) was built in 1898 under a shroud of secrecy, and christened by Lady Russell of Killowen at its launch on 26 June 1899. Shamrock featured a composite build, with manganese-bronze bottom and aluminium topside clinkerbuilt over a steel frame and a pine decking