Murder by the Dozen

Jan Kokk, Curacao's brawny answer to Belgium's impeccable Hercule Poirot, is kidnapped by the scheming security officer--attractive female, of course--of an oil tanker plying the Caribbean. Kathlee hopes Kokk will discover who is murdering the ship's twelve-man crew, one by one.
Which of the crew is the murderer and why is he killing all his mates?
The motive remains a mystery until the ship--minus crew--reaches Nicaragua's isolated Little Corn Island in the Caribbean.
Kokk's sleuthing fails to deter his interest in the lovely security officer, who just happens to be the daughter of the shipping company's president.
Come aboard for another test of Jan Kokk's skills, both detecting and doting.