Watch the video: NI woman Shirlee Beggs films strange 'Unidentified Flying Object' on Mediterranean cruise

Shirlee Beggs was onboard the Celebrating Reflection cruise ship in late August with her husband, when she witnessed a “bizarre” sight, which she described as a "large round light” moving around the sky.

The cruise ship had left Nice and was travelling towards the Italian port city of Livorno on the west coast of Tuscany, when bad weather struck.

“We had been told there was going to be a storm, but it wasn’t actually that bad,” said Shirlee.

"I quite enjoy storms and I had seen some flashes so I had gone out onto the balcony to have a look and see what was going on and then had taken a few nice photos of the lightning.”

Shirlee said she then started to video because “the sky was going a bit strange” and it was then she spotted the large ball of light.

"It was very bizarre, because it was jerky, it wasn’t staying still. It was nearly like a rubber ball, bouncing off something. It was moving at a considerable speed. It was very, very strange.

"I literally just stood with the phone as still as I could keep it and took some video. I also tried to take some photos of it.”

Shirlee said no one else was outside their cabins because of the storm, so she’s not sure if anyone else onboard witnessed the sight.

The video, taken around 11pm, is about 54 seconds long and quite clearly captures the ball of light.

"I showed it to my husband and said ‘I’ve got a UFO’ and we started laughing, but then he said ‘what is that?’".

Shirlee added: “I don’t believe in UFOs, as in spaceships and aliens and all that sort of thing, but I do believe in UFOs as in Unidentified Flying Objects, which is what I was thinking. We were quite far out from shore, for it to be something like a drone, I did not think that at all. I just actually didn’t know what it was, but I knew it was something peculiar. I stood watching it and then it just disappeared, it petered out.”

Shirlee said she wasn’t frightened by what she saw, but was “excited”.

When she came home she showed the video footage to friends and family, who offered up their theories on what it could be. She said when the image is enlarged “it’s nearly like a comet, but with a circle of light around it."

A couple of people suggested to Shirlee that what she saw could be ball lightning, a very rare phenomenon that involves ball-shaped lightning that moves much slower than normal lightning. Ball lightning has been reported to be as large as eight feet in diameter and can cause great damage.

"I had never heard of ball lightning before, so I Googled it and watched a few videos and they looked very similar,” she said.

Shirlee said is sharing her video in the hope that someone can shed light on the odd object.

“I would love someone to tell me what it is and if it is indeed ball lightning,” she said.