Well, it's unisex, since it's listed under both: link
EDIT: Also, google shopping
About half of them will list them as men's, but I believe it's the exact same watch, since, when I complained to them via email about women having some cool colors that men didn't have access to, including the one I listed as "one I was going to get" and the purple one, they responded by adding those watches to the men's side.
What's cool about Nixon is that they run the gamut from traditional/conservative to wild/crazy. Look around, you may find something else you like. Nixon Women's Watches. They are in order by decreasing price -- the ones towards the top of the page are typically the most expensive.