When I was diving at the Blue Hole in Dahab last year, which was during the Eid Al Adha holiday, there were hundreds of Egyptian snorkelers in life jackets being towed around to look at the Blue Hole.I'm guessing this woman wasn't wearing a life-jacket. She'd still have some risk of drowning even if she did wear one, but might have cut that chance down significantly. (I've never snorkeled with a life-jacket, but it seems like you could make it work, with some adjustments.)
Someone tried to crawl over me when we surfaced to exit the area, it was crazy.