I have this problem only when diving in cold water, for some reason (70F or under, approx. - it's cold to *me*, anyways!), and I'm female, for those looking for gender statistics. I only ever noticed it when people pointed it out on the surface, so I can't tell what depth it started at, but since then I've started checking to see if I need to rinse my mask out before anyone sees and freaks out (and it's always the big guys that are freaked out about it, too!), and never noticed blood in warmer water.
That, and I don't get the ear infections in warm salty water, too...good a reason as any, when combined with new airline restrictions, to refuse to go back to Canada...
That, and I don't get the ear infections in warm salty water, too...good a reason as any, when combined with new airline restrictions, to refuse to go back to Canada...