I know what they are, watch caps. Or as we call them in the CA law enforcement circles, a 211 hat...
lol! Up here in the northeast it is the style to wear a P-Coat. I recently bought one and I was given a watch cap as part of my equipment for volunteering. Having the beard, P-Coat and watch cap on, makes me look pretty scary. The black gloves help too.
The watch cap is very light, but very warm.
http://en.wikipedia.org/wiki/Pea_coatRetail Price: Approx $400