The Manannan will start its 2015 sailings on March 26, the Steam Packet has announced.
The fast craft will cover its usual routes to and from Belfast, Dublin and Liverpool.
This year Manannan will operate an additional 48 Liverpool sailings in response, the Steam Packet says, to customer demands for more services.
The first of the season’s Irish sailings takes place on April 1, to Dublin, with the Belfast service resuming on April 3.
Chief Executive Mark Woodward says over the winter, Manannan has undergone some repairs and refurbishment, and the removable mezzanine deck which will be installed during the TT and Festival of Motorcycling has been completed.