Wild Thing by Josh Bazell, 388 pages

Dr. Peter Brown is still hiding from the mob and is currently known as Dr. Lionel Azimuth.  When the story begins he is working on a cruise ship as a crew physician.  You'd think it would be a fun job, but nope.

He gets a call from a contact in witness protection who asks him to do a favor.  A reclusive billionaire is looking for a doctor / protector to go with sexy paleontologist to find out if a supposed lake monster is really a lake monster or a hoax.

Cursing and bad guys follow.  Not as good as the first Dr. Peter Brown book, "Beat the Reaper" but still a fun read.