I arrived at the nest site at 12.55. When I walked down river I had not seen any Dipper and this encouraged me, I suspected that they would be by the nest, and I was right. I tried to approach very carefully, realising that any disturbance is going to be made when I arrive at the nest, particularly if one or both birds are there. Unfortunately that was the case and one bird was disturbed and quickly left the scene. I was disappointed of course and a bit upset that I had caused it to fly. I quickly got myself concealed and I was very relieved that I hadn't caused too much damage because both birds arrived together at 13.31. I was now sitting in a different spot just a bit further away because I really don't want to get too close. They approached me from up river and quickly landed on the boulder together. This surprised me because I hadn't seen that the bird, there when I arrived, had flown past me . In short, I was expecting them to arrive from the other direction. The female immediately went in to the nest but I hadn't seen if she was carrying any nest material. The male remained on the boulder as you can see, bobbing up and down and fluttering his wings in a display to the female. The male is excitable and never stops bobbing and dancing. They stayed for 10 minutes in total, the female eventually leaving the nest. Then they were both on the rock together and I tried to get a good shot, but didn't really 'pull it off" but it's worth posting for the record.