Ive seen these searchlights used by nightclubs.Trust me it wasnt that. I guess its a 'you had to be there moment'..The lights (...) continued in this formation all night (...) the formation would end and start again on a loop resetting all night (...) the constantly looping and resetting formation of the craft made me think of something that might have been automated somehow.This went on for literally hours and we went to bed at 6am and it was still continuing.I kid you not.
Sounds a lot like high power spotlights - like searchlights, but with a much narrower beam specifically to make attention grabbing displays at high alitude. From nearby the visible ground level beams (think 20th Century Fox logo) guide punters to whatever premises is running them. They are programmable to run in combinations of elliptical and figure 8 patterns.
When the (then) Point Depot (now O2 arena) started using one to signal events, lots of people started reporting sightings all over the suburbs many miles away. There are a number of companies in Ireland that rent these out to nightclubs and parties. With special permission Lasers can sometimes be used, some of the effects with the right atmospherics can be very 'convincing'.