Cinnamon Skin — John D. MacDonald

When Travis McGee's friend Meyer lent his boat to his niece, Norma, and her new husband, Evan, he never dreamed he was signing their death warrant.

For suddenly, out in the waters of the Florida Keys, the boat was destroyed by an explosion. To all appearances only Norma, Evan and a crew member were aboard when it happened.

But Travis McGee begins to suspect it's not that simple. Is the Chilean underground responsible? Was the explosion connected to drugs? And why does it seem that Evan may not have been on the boat when it blew up? All good questions for the incomparable Travis McGee, who sets out to trap a very elusive and deadly killer.