Mating pair periodically dipping down to lay eggs.
A lot of them around the lake. Variously pictured: a male eating a female Common Whitetail (and a blurry shot of him snatching her off the lake), a female ovipositing in mud cracks at the water's edge, and a mating pair with the female ovipositing off alternate sides of the reed they're perched on.
We watched a male patrolling over a female ovipositing in the lake, until she was snatched up by a Common Green Darner and carried off to the bushes to be eaten head-first!
Lots of these little pink-red fellows in the tule.