I think I finally figured it out. Just like the section titled The Shark having a shark that died in the very next chapter, the whole big scary orca premise was a total bait-and-switch. The titular orca is actually the hero of this book, and Jack Campbell is the monster. It's kind of like Moby Dick if Moby Dick was much smaller scale, and the book lacked a moral center, a sense of tension, a straightforward well-crafted plot, fascinating characters, or literary quality of any kind.
Hey, at least Jack's not actively thinking about sex with his sister anymore, right? Maybe this is the start of an interesting character arc. Probably not, but maybe.
--
Music:
"Epic Unease"
Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 3.0
http://creativecommons.org/licenses/by/3.0/