Helpfully, ST had left a message following my first visit to the Pond: "I have only found the Blue-tails around the larger pond, on the road-side edge", he had written, so that was where I headed first. After a short time, I came across one, was very excited, took lots of pictures, moved on, found another and took more pictures. Later, while having my picnic lunch back at the car, I opened the field guide to check the points against my pictures. I had taken many very nice pictures. Unfortunately, the Blue-tailed damselfly in every one of them was an Emerald!
How could I have been so confused? Who can tell? I was reminded of an incident many years ago when a very loud lady in a small bird-watching party shouted big white seagull coming towards us and everyone looked away from the rare-ish winter visitor we had been watching to see a Mute Swan flying westwards. I hoped things couldn't be that bad.
Despite this set-back, I started the afternoon in a positive frame of mind. Returning to the Pond, I followed my morning route and was soon rewarded with a male Blue-tail; an actual Blue-tail this time (I checked all the points). It was almost hidden amongst the pond-side vegetation and in tandem with a mature infuscans female. Stepping daintily upwards through the undergrowth, the two eventually perched on a rush and as I watched, they joined in a copulation wheel. The picture records the scene ... and this new tick on my D&D list.