Since "The Blair Witch Project" debuted, so-called "found footage" movies have exploded. When done well, they can be extremely terrifying and satisfying at the same time; sometimes there's nothing scarier than seeing some messed-up stuff go down on a hand-held video camera, because it's like you're watching someone's home movies. It's real, it's not terribly effects-laden, and it can convince you that there really are horrible things living under your bed. Among the group of "well done" are "REC" and "Paranormal Activity", which has spawned two more films to the delight of fans.
But sometimes these "found footage" films make the viewer grow weary. You're following a shaky camera for an hour and a half with very little (or no) explanation as to why someone is still holding a damn camera while the world around them is going to hell (example: "Cloverfield". The group is literally running for their lives over a bridge jam-packed with bodies, yet the cameraman is still filming. Maybe it's just me, but I'd probably ditch the camera in favor of getting my butt to safety).
I'm not sure which category "The Bay" falls into yet; I'm sure I'll watch it, being a horror fan with a rather large curiosity gland, but as of now I'm just not sure about it. The major thing the trailer has going for it is that everyone--I don't care who you are--has that fear that there's something in the water. Here that fear is played upon not only with physical manifestations, but on a viral level as well. What if something in the water made us not just sick, but flesh-eating sick? It's already happened to at least three unfortunate people in the American South this summer; a college student suffered several amputations because of bacteria in a lake which entered an open wound. And leaning on the audience's fear of a very real thing could be just what "The Bay" needs to help it score big at the box office.