 SS "Riviera" was laid down by William Denny and Brothers at their Dumbarton, Scotland shipyard as a fast packet for the South East and Chatham Railway's Dover and Folkestone to Boulogne runs.The ship was launched on 1 April 1911 and completed later that year.She was requisitioned for service by the Admiralty on 11 August 1914, and was commissioned on 6 September after she was modified to handle seaplanes by Chatham Dockyard.