How bad is it? It's neither as good nor as bad as the title would have you think.
Should you see it? Depends: Just how badly do you need to see augmented breasts?
Carmen Electra plays a professor leading a class on a cruise ship that wrecks on an atoll that begins to flood. Then the shark attacks. Brooke Hogan (daughter of Hulk) is second-billed. There's no explanation as to why the shark has two heads, why it's so huge or why it can swim in shallow water - and on land - when that large. The film has standard CGI and one very bad rubber monster and zero believable breasts. The dialog consists mostly of "Run" and "Oh my God!" This is probably the last shark film I'll review here - they're starting to become indistinguishable.
Update: I have one more shark film on my list of reviews...