A suspected chimney stack lagging fire was detected on the Ben-my-Chree this morning.
It's estimated to have started at around 8:45am on the crossing from Douglas to Heysham.
Steam Packet engineers have since contained the blaze, completed their investigations and gave the vessel the go-ahead to continue on with her journey.
No passengers or crew have been injured and there's no significant damage.
The ship is now travelling to Belfast as scheduled.