I mostly hang out in the tech and truck camper sections, and I feel like I am the only woman there. But it's true we can't always tell from usernames.
As for guys talking endlessly about stuff -- I've been criticised here several times lately for doing exactly that! I guess by the guy code it is ok if you are talking endlessly about theoretical/scientific details, but not about figuring out what will work best in a particular weird situation?
I've been the only woman many places, throughout life, and I am still figuring out the guy rules ;).
Maybe we need a ladies' lunch hour sub-forum?