Zygo it is - but I didnt realise just how many different species and hybrids there are. Checked out an "authority book" but I'm still confused. There seems to be so many variations of the main (blue?) petal. Anyway, thanks for the help
Mine also looks a bit like pics I've seen of Blue Lake plus (unfortunately) to my eyes, several others ! I guess thats the problem with hybrids, and orchids do seem to have more than their fair share of them.