I know, everybody makes a pun on the Hertfordshire town's name. As we passed Swain's Mill, now a car workshop, in Ware on the Lee Navigation in August, I thought I saw one of the mechanics wave as I pointed the camera. It's only now that I've tweaked the picture that I can see that he did indeed wave.
This is in the central dark opening in the top picture.
Why do people do it? It must be that a boat is still a comparative rarity, and still seen as somehow exotic. That's fine by me!