In this video on board the ISS, CSA Astronaut Chris Hadfield wears his watch very loosely--so that it continually bumps against different sides of his arm. I imagine this might be mildly irritating or get in the way of precise work, although it is possible he simply does not mind. from looking at pictures, it seems like Hadfield often wears his watch this way, and I have not yet found any evidence of another astronaut wearing a watch loosely.
This makes me curious--why might an astronaut wear a wristwatch so loose? Are there aspects of an astronaut's work, zero-g, or the ISS that might explain this--perhaps something to do with concerns of constricting blood flow in microgravity? Is there evidence of other astronauts wearing their watches loosely?