However, by the time we were off the mouth of the River Stinchar, it was obvious that she was much bigger than Pharos.
Time to consult the maps. "Nope, she's definitely not on the OS 1:50,000" "That's funny, she's not on the Admiralty chart either! I wonder what it is?"
Although both the map and chart had been unhelpful, ShipAIS came to the rescue. She is North Sea Giant. She was launched in 2011 and is the World's tallest Offshore Construction Vessel. Her length overall is 160.9m with a 30.0m beam. Her gross tonnage is 18151T, which makes the Pharos, at 3,672T a relative midget.
She was holding a geostationary position above the Moyle Interconnector cable, which carries electricity from Currarie Port, Scotland to Ireland. The cable has a number of breaks and North Sea Giant has been replacing damaged sections of the cable.