George Harmon Coxe 
Slack Tide [EPUB ebook] 

A marina owner gets caught up in a murder investigation The girl in the water is unfamiliar to Don Mac Laren. This is odd since, as the owner of the island’s only boat dock, he knows everyone who steps foot on the small spit of land. He hoists the young swimmer out, and is helping her get warm when Oliver Kingsley, the island’s wealthiest citizen, comes to collect her, claiming he’s her husband. The girl refuses to leave with Kingsley, resulting in a brawl between the two men.In the morning Kingsley is found dead, and after the cops learn about the fight, they peg Mac Laren as their chief suspect. As Mac Laren struggles to understand the mystery behind the rich man’s death, he finds that even the smallest island can hold deep secrets.