I've witness a Coxn ordering a female sailor to shave her "beard" because she requested to be "Excused Duty Watch and FF duties while at sea and alongside". She complained that she couldn't get a seal with a CHEMOX mask because, and that was on her memo, of the extensive facial hair on her jawline caused by hormone replacement therapy medication prescribed to her by an MO for her premature menopause. No joke!
When the Navy started heading to the Gulf regularely, it was left to the CO to decide whether or not his sailors would be sproting beards. Some allow them as long as they were short trimmed and others just shorn the crew. But when they were coming home, the beards were back on. A couple of years ago, a MARGEN came out and officially passed the power to the CO. Some CO were shaving for operations purposes, others the whole time. On my last ship, we went from a CO that allowed beards except in operational theatre to one where beards were shaved off at all time. I guess it's a policy now.
Personally, I'm all for sporting a beard. Some of us are way to ugly to be bare-faced.