Peter Benchley's 'Jaws' is a book very much of its time: there are some characters that resonate the recent history of America (Hendricks, a Vietnam veteran with obliviously homophobic undertones- a role significantly reduced in the film). There is also a somewhat mysoginist view of female sexuality (a discussion about sexual fantasies in the book focuses shockingly on Ellen Brody's apparent desire to be raped- that's no way to flirt)... but if you're going to read 'Jaws' for informed social commentary, you've probably picked up the wrong book.
When Benchley isn't concerning himself with domestic issues, class conflict and shady political dealings (something he is clearly interested in exploring in Part Two), he excels at constructing taught, tense sequences that move at such a thunderous pace they are actually heart-pounding. The opening sequence is much what you would expect having seen the film, as is the inevitable finale, but the difference between this book and the unsurpassable movie that it inspired is largely in the characters. A major supporting character is entirely excised from the film (journalist Harry Meadows), the touching connection Brody has with his sons is absent from the book, and Hooper is an entirely different animal altogether.
There are some incosistencies within the book; in the first two acts, Benchley seems unsure whether to follow the shark or the effects it has on the small town leading into an entirely unnecessary and uncomfortable emotional betrayal (it's here that Benchley shows weakness) and also giving too little focus to a subplot about Mayor Larry Vaughan's shadowy mafia connections (perhaps something better left hinted at rather than exposed- I don't entirely understand the point of the cat sequence at all). The book is quite largely devoid of any true wit, something the screen version has in spades. But in the characters of Brody and Quint, Benchley has created something that the screenwriters couldn't avoid. Quint is very much the Ahab seadog we see in the film (if not quite as developed as Robert Shaw's outstanding turn) and Brody is still the conciencious everyman trying to do the right thing, even though it terrifies him.
The third act is rewarding, and equally as gripping as the film's- but it's that screenplay (co-written by Benchley with Carl Gottlieb) that just outdoes it. Benchley was right to make changes for the adaptation, it's simply better. That's not to say that this book is not worth reading. On it's own merits it's a taught little thriller, with some stomach turning depictions of the shark's numerous attacks, and I really relished some of the elements that didn't make the final cut of the film. If unfaithful adaptations are bad, then Spielberg's 'Jaws' would be an awful film. Sometimes changes need to be made, and I think that these two different versions of 'Jaws' should be appreciated in their own right. The novel could've been a little leaner, a little more to the point- but it's those diversions that add to the palpable tension and create an atmosphere of unrest and incredible power in what has to be one of the most grippingly cinematic conclusions to a book I've ever read. Part Three of 'Jaws' doesn't waste a word, leading me to suspect that some of what preceded it was just a bit of padding. Still, when you finally get out on that boat it's just flawless.