I was initially unsure what star rating to give this film, as it really is one of the most poorly scripted, filmed and acted films I have ever seen. The majority of the shark footage seems to have come straight from the Animal Planet basement. The sound is poorly synched for half the film, giving the impression of a film that has been dubbed into English. The script sounds like the dramatic equivalent of congealed monkey vomit; the best line of the film is unrepeatable here, but please watch out for when John Barrowman begins to say, "hunting for this shark has got me really wired..." and listen to what he suggests next.
Special effects-wise, this film is also significantly lacking. The giant shark repeatedly changes size during a five minute sequence, from having a mouth big enough to swallow a lifeboat full of people, to being just big enough to swallow a single person whole. This may be because the "special effects" are really just 15 seconds of footage showing a shark jumping out of the water which have been scaled up and down (possibly on Windows 95) to suit.
However, due to this and much, much more in the way of implausibility, plot holes, poor effects, scripting, dubbing and acting, it is one of the funniest films I have seen for a long time. Watch it with your friends, scream with laughter, then recommend it to everyone you know. But be warned: if you want any real scares, please get "Jaws" instead.