Safari is a Stanley Hastings Mystery, by Parnell Hall
Book nineteen available in Audible , Kindle, PaperBack or Hardbound.
I read the hardbound edition. 

Mr. Hall is a well established author who writes with skill and provides depth to his characters.

 My Review  

Stanley's Hastings character is spot on in every detail. You can imagine this guy in your mind, and be in his moments, such as when he spots a sexy young woman on a plane, or when he's on the case, but wryly seeming off the case.  The detective Mr. Hastings, is a very clever character. 
    Safari is just that, a middle aged couple seeking some adventure in their lives, takes a trip to Africa, Stanley's wife Alice is thrifty, so she books a cut rate adventure. Alice also tries to upgrade their status without paying extra, which provides some humorous thoughts and comments from Stanley. 
   Someone from the tour group or guides has a secret, and it is imperative that no-one finds out what that secret is. As you follow the tourists and have breakfast with them, dine with them, and share their concerns while you're immersed in the story through Stanley's point of view, you'll wonder who is the culprit of a crime. But you'll be wrong. That is where Mr. Hall's strength as an author comes in, he'll take you write up too the last pages, before you know who created the Safari where the animals were not the biggest concern of the tourists. 
   This book is  Five Full Sails  

Do you like to listen to your books, Checkout Safari on Audible