In reply to Parrys_apprentice:
It was all in house training at the courses I have worked on. every so often there was a spot check of either a full session or a senior instructor just popped up to have a look at your session then popped off again.
As there is currently no "standard/official" NGB for high ropes courses in the UK (That I am aware of, other than ERCA), most places just have in house training, with standard random supervision by the senior instructor.
However, some courses I've heard of, do like some form of climbing background, often an SPA.
There will be a lot of changes around this area over the next few years. We provide consulting for a number of independant high ropes courses and we strongly advice on using ERCA qualified instructors for a whole range of reasons.
Please feel free to get in contact if you require further information