Severe fog is preventing the Ben-My-Chree ferry from berthing at Heysham.
The ship is unable to divert to Liverpool as visibility there is also very poor.
If there is no improvement the ferry will have to return to Douglas.
A spokesperson for the Isle of Man Steam Packet Company said: “Because of fog more severe and prolonged than that forecast, visibility is less than that permitted by Heysham harbour regulations to allow safe berthing.
“The forecast is that fog may continue to be a problem for the rest of the day.
“However, there will be a sailing this evening and passengers should check in at 8pm.
“However, passengers should be aware there is a possibility of a similar scenario, where berthing may again not be possible in Heysham, and should adjust their travel arrangements accordingly.”