The Royal Navy aircraft carrier HMS Ark Royal suffered an engine room fire just hours after setting sail for the first time following a £12 million refit.
The 20,000-tonne warship sailed out of Portsmouth Naval Base last Friday to embark on two weeks of post-maintenance tests.
But within hours, as it sailed past the Isle of Wight, a sailor had to use a fire extinguisher to put out the blaze.
A Navy spokesman said: "It was a minor fire put out by a sailor with a fire extinguisher and a chemical spray.
"Ark Royal is on post-refit trials at the moment and the whole point is to iron out teething problems, it is part of the course.
"We do not expect to have fires but sometimes with new equipment there is a risk and the ship's company was aware of this.
"There was no damage, no injuries and no impact on the ship, which carried on with its programme."
The ship's engines were overhauled as part of the seven-month refurbishment work.
The upgrade work, carried out by BVT Surface Fleet, also included painting the hull with new "Intersleek" paint, which enables it to cut through the sea more quickly.
This reduces fuel and emissions by 9% and also increases the ship's top speed by two knots to 30 knots.
Other work included new exhaust systems, an updated IT network and improvements to the sewage treatment plants, gearboxes and diesel generators.
Once the sea trials are complete, Ark Royal will resume its role as fleet flagship in the new year, taking over from its sister ship HMS Illustrious.