cool things with wheels since 2006
The spotter's left hand tells you how much experience he has at this.
truly. He is something to see... his gestures are sharp!
I've done traffic control, seen people on aircraft carriers do hand gestures, and watched a lot of crane operators / supervisors - all hand gestures, but I've never seen anyone as smart appearing as him at work. I don't mean IQ, I mean commanding, precise, deliberate, and planned. He does the right amount of movement to be seen, a bit over exaggerated so no one mistakes what he's doing, but sharp so they don't think he's getting tired and they can take a break.
It is especially impressive to see him stand at the edge of the quarry and direct two excavators at the same time.