We did it at our meet in Indianapolis in the 800 free relay and the 400 free relay and it allowed us to beat Ball State.
My swimmers know exactly what I mean when I just whistle and point.
I don't get real vocal in a meet, but in practice I can get vocal.
There's really nowhere they could look to see me. You figure out ways to communicate in an environment where it can sometimes be difficult to hear.
There's signals for just about everything from balancing your stroke, to getting a swimmer more into their turns, to just yelling so they know to get going.
I'll whistle sometimes, and they can pick out a voice.