Better than the 2005 film and "The Deep"
I wasn't all that impressed with either 1977's "The Deep" or the film it inspired 28 years later, 2005's "Into the Blue." They were decent oceanic thrillers but that's about it. I liked the actors in both -- Nick Nolte, Robert Shaw & Jacqueline Bisset in "The Deep" and Paul Walker, Scott Caan & Jessica Alba in "Into the Blue" -- but unless you're rabid fans of Bisset and Alba (or the guys) neither film ever rose above the level of average.
Direct-to-video "Into the Blue 2: The Reef" (2009) is a sequel-in-name-only that successfully builds on the template of those other two flicks and, surprisingly, offers a far more entertaining experience IMHO.
"Into the Blue 2" simply has a more engaging story, more dazzling filmmaking and superior women (on the whole). In other words, everything that you might be looking for in an island thriller is here, only better than those two earlier pictures. Although the main cast is relatively no-name (Chris Carmack, Laura Vandervoort, Marsha Thomason & Dave Anders), they do a splendid job; plus the film is highlighted by two solid cameos of Parvati Shallow ("Survivor") and Audrina Patridge, both gorgeous. Another highlight is the ultra-serious and thrilling final act, which comprises the last 35 minutes or so. Up to that point the story is pretty much just a fun, light-hearted beach/diving flick. The dramatic change in tone works in the film's favor and keeps it from being one-dimensional.
Since "Into the Blue 2" was a direct-to-video release it cost a fraction the expense of "The Deep" and "Into The Blue," the latter of which cost a whopping $50 million, believe it or not. This makes an interesting study: Filmmakers can make better films at a fraction of the expense; it's simply a matter of ingenuity. Hats off to director Stephen Herek, writer Mitchell Kapner and the cast - awesome job!