Large, well lit up, unidentified craft at sea level rose and flew into night sky before disappearing.On the night of Monday 26th June, I was working night shift on an oil rig in the Southern sector of the North Sea. I won’t give the name of the oil rig but the closest marker to it is buoy 62144.We are not allowed cameras or phones outside on the platform as it is a hazardous area and it is an ignition risk so I will try my best to describe what I seen. It may be a bit clumsy.At approx. 2330 hours, I was working outside and needed to urinate. Rather than go up the many flights of stairs and all the way into the accommodation I decided to urinate over the side, into the sea.I proceeded to the South side of the platform and in front me was what at first I thought was a helicopter, we sometimes get emergency flights at night.Once I had taken in what I was looking at it was clear to me I wasn’t looking at anything I had ever seen before. It was very close to me and close to the surface of the sea.I will try my best to describe it--A large oval shape, cannot say what size, as there is nothing close to gauge it against. I am guessing it was the size of a medium sized plane. It had coloured lights around its centre, and these were moving from left to right, changing from red, blue and green. It had a large amount of white light emanating from the bottom of it, this is why I thought it was a helicopter, it looked like a massive searchlight focussed on the sea. It was extremely well lit up.It didn’t appear to be moving, or was moving very slowly at first but more looked like it had just surfaced from the sea.There was another red light much further and higher to the South of this one.I watched it for approximately 20 seconds, then decided to fetch my two work colleagues.By the time we got back it had flown a considerable distance but was still clearly visible.It was heading in a Westerly direction. By this time the shape wasn’t discernible but the lights around its centre were still flashing from left to right but this time only appeared to be red.The stand by boat for the rig was close by and was pointed directly at it. There was also a reasonably sized manned rig over to the West.Regarding sound, I was working in a reasonably high noise level area and had ear defenders on but I didn’t hear anything. If it had been a chopper for example I would still have heard something as there are about 6 flights a day on here and you can hear them even with ear defenders on.The light that was coming off it wasn’t exactly subtle and it was clear it didn’t care about being seen. I am struggling to process exactly what it was I did see.I am glad my 2 colleagues also witnessed it, albeit at a much further distance. It was like nothing I have ever seen and until my dying day I will never see anything like it again.I have looked on line to see if any images come close to help me describe it and the one that looks most like it is the Roswell photo. The colours best to describe it are in an image of a ufo with Tom Delonge.I’m attaching both to help with my description.I am stopping to tell people now because I am not being taken seriously and am in danger of being seen as nut- which is fair enough, as I know how it sounds. I hope you believe me, you must get loads of these, but if not I feel better just for sharing.I want to document it officially before my memory of it starts to cloud. (It never will), but don’t know how.I also don’t know who to contact to see if any other witnesses who also spotted something but this is a start. If the crew of the stand by boat were looking outside they couldn’t miss it.Looked very much like the black and white photo but the lights around the centre were like in the second photo.The light at the bottom was slightly different, appeared to be more than one.I will never forgive myself for not getting a photo or filming it.