Peter Benchley's White Shark
 

"Jaws" is most likely one of my favorite books of all time, and, while not exactly horror (I'd put it into more into the thriller/drama category), it still has the ability to scare. "White Shark" (A.K.A. "Creature) is a lesser known novel, which, despite its rather clumsy title, is not really about a shark, so don't expect a re-hashing of "Jaws", although it does have a similar setting and is stylistically similar, there is more of a scifi/horror element to the novel, and Benchley's suspenseful pace makes for one of the most genuinely freaky, thought-provoking books I've read in a long time. There are a lot of scary moments to be had here. It is, unfortunately, very under rated which has the added effect of making it sort of rare, but I am sure a library may have it, and Amazon.com almost certainly does.