For me, I'll just play games with them underwater. I always enjoy playing the cat and mouse by just easily kicking until they give up. I have yet to find a dive buddy that can keep up and they invariably run out of air 1/2 way into the dive. But that is a mean thing to do and you have to be ready to either dive solo or surface with them (not really good choices), but the point is just let the fins to the talking. I have done races in the pool with people and that shuts them up pretty quickly as well.