There is very little way to describe this behavior. Basically, the male and the female face each other with their bodies and heads just above the water level. Then almost instantaneously they get up on their feet and move in unison together for 10 to 30 m. It is a very impressive display. One really needs to be quite aware of what is going on before this event occurs. On the reservoir in Southern California where we witness these events, we probably saw 30 or 40 exchanges just like this at varying places on the lake. Best observed from a boat but one can also see this from the shore.
Is this a composite: No
ISO 500, 400+1.4 X. F7 .1, 2000th, handheld from a moving boat