There's a low, guttural half-scream of agitation before River launches herself forward in a not at all graceful, entirely fumbling move. Not to hit him, or hurt him.

Just push. Just make him be away.

"Go swim!"

She reels back, stumbles over her own feet, holds her sides to stay steady.

"Polymer bound shoes, it's why we're here. Swim with them!"

...in hindsight, it was probably a bad idea for anyone to introduce the Earth-that-was concept of the mafia to River and then explain the phrase 'sleep with the fishes.'