HSC Manannan is a high-speed catamaran car ferry owned and operated by the Isle of Man Steam Packet Company. She arrived in Douglas on 11 May 2009 after a major refit in Portsmouth. She was renamed after Manannán mac Lir, the Celtic god of the sea, and made its maiden service voyage with the Steam Packet Company on Friday 22 May 2009 with the 07:30 sailing from Douglas to Liverpool.
Manannan was built as Incat 050 by Incat of Tasmania, Australia in 1998.
She operated for a short period as a commercial ferry for TT-Line under the name Devil Cat before being acquired by the US Navy and converted for military purpose.
US Naval service
She commissioned as Joint Venture in 2001, serving for five years with the US Military Forces.
She was handed back to Incat in early 2006 and underwent a refit and painting in the Express Ferries livery. She was planned to enter service with them as a car and passenger ferry, but this never materialised.