(http://i.imgur.com/6RYy1.gif)
Clearly he is cranking.
he's practicing his mad punching movements of course, you always need to be ready in case of a water-system malfunction. you never know when a valve might just want to take control of the ship.
You know, I've seen that scene several times and never noticed it. Man, I am not as observant as I thought I was x_x...
King