HarveyPerkins, I know very little about damselflies, and it's only in the last week that I found out just how many species were present on the dams here! So for my own knowledge, I'm interested in the reason you came to this identification. When I looked at other sightings it seemed that the abdomen of this insect was most like the Alpine Flatwing, but of course the head and thorax were not, I'm fairly sure that I saw other Common Bluetails here, and have posted a sighting. Interested to hear your thoughts.