This is a terrible movie. It's not believably even as a work of fiction...
In fact, I will go as far as to say the worst I have ever watched. It was difficult to watch till the end.
Why do you ask?
unrealistic, hard to believe, weak plot
Terrible CGI, clearly low budget which I can take but not when every scene is CGI. The water is so clearly fake it is shocking. I'm sure water is hard to animate but in this movie, it's in every scene! Not ideal
very unsubtle in promoting a swimwear brand that clearly paid to be included (why you'd want to be associated with this film I don't know)
Pretty much everything in this movie is badly researched or not researched. The surfing was awkward to watch, the shark behaviour isn't in any way realistic, even the way it swims is not right!
My favourite part was when the shark somehow bit clean off a mouthful of 2-inch steel platform on the buoy, and then the buoy seemed to transcend physics and topple over for no reason!
To make a thriller thrilling you need to get people to believe the events are taking place, even if its a purely fictional piece. There wasn't one part of this movie I found remotely believably! I don't understand how it has so many good reviews...