This movie is pretty much at the top of the bad movie food chain. I laughed at literally every scene, I don't know how they managed to make a simple thing like the hero typing an email funny but they did.
The first thing you notice about the movie is the shark is either shown as shark footage (which is fair enough) or something that looks like it was made in Microsoft paint. I'm guessing bad actors are drawn to bad scripts like sharks to chum and this chum is especially fishy. Witness the security guard who just has to say a couple of simple lines but is quite clearly reading from a cue card he can't quite see. Most movies would cut him out, especially as the scene is pointless.
I also especially liked the helicopter pilot, if a man doesn't twitch a muscle at the sight of a 100ft shark then it's hard to imagine anything in life really moving him. Maybe he's just feeling down because his helicopter is quite clearly a toy or maybe he's just bemused because the shark grunts like a pig throughout the film.
The best scene doesn't involve the shark at all. They're stood on the beach and our hero delivers one of the worst lines ever written. If you've seen the movie you know the one, if not then you have the right to discover the beauty of it yourself.
Probably the funniest film ever made, no bad movie shelf is complete without it. Fingers crossed they make another one with the exact same cast and writer.