So far ALL the water I've dived has been under 70 degrees. The cold just doesn't bother me all that much. If I touch a freshly submerged hand or foot to another's bare skin, I can elicit an outraged yelp, but my core stays warm. On the few dives where I actually have gotten quite cold (usually following being seasick), I was feeling the cold through my chest and abdomen. Having cold fingers and toes doesn't bother me. Traditionally, I'd go 54+ degrees without a hood. Now that I *finally* found a hood that doesn't suck and I'm doing a lot of photography, I wear it more often, but over 58 and it goes bye-bye.
While I know several cold-water sisters, I've noticed a dearth in the population of them. When I went out on a three dive boat yesterday, I was one of two women on board, and when I did a three day lobster trip in the Channels, I was the ONLY woman on board. I'm not sure about who tolerates the cold better. Most of my buddies are male, but most of my buddies have drysuits, and a few times, they've still gotten colder than I have. The women that I do dive are usually pretty hard core, and can smoke me in the tech department.
There doesn't seem to be much of a macho component keeping us out either. I haven't gotten the "you're just a girl" attitude from much of anyone, and though I've dived with a couple of fast-pace divers, which is incompatible with my dive style, generally I hang out with other photographers or slow divers, they don't treat me differently, fun times are had, or I'll occasionally "same ocean" dive with spearfishers, benefit from the larger life forms they attract, and help them eat their catch later.
I'm not sure why it doesn't attract more female divers? We have cute, friendly harbor seals, and fluffy sea otters?
I do wonder... such a significant number of people around here dive drysuits, and that can be more of an issue for women...