Rolling in the Deep

It's barely a book, a slim horror novella where we get a reality show out on the ocean in a cynical attempt to discover mermaids. Armed with begrudging researchers, a hardened crew, shallow TV talent, not to mention a couple aces up their sleeves it's not without a bit of shaudenfraude when the expedition goes horrible south.

And much like Cabin in the Woods - when the mermen finally appear, it's bloody, but over all too quickly.