Those on board are expected to have a crossing time of four hours
The Isle of Man Steam Packet Company has delayed the departure of the Manannan due to weather conditions.
The sailing is being pushed back by an hour and is expected to leave the Island for Liverpool at 3pm.
The Ronaldsway Met Office is forecasting strong southwest winds which are likely to ease throughout the afternoon.
Passengers are being asked to check-in no later than 2.15pm.