The Last Fathom

From Author Wars - https://authorwars.com/publications/the-last-fathom-240521.html

Overview:

Title: The Last Fathom
Author: Martin Caidin
Year: 1974
ISBN-10: 0523004834
Publisher: Pinnacle Books
Price: $1.50
Pages: 306
Binding: Paperback
Type: Novel
Title Reference: The Last Fathom
Notes:
"First printing, November 1974"; no number line The artist is not credited, no visible signature on the artwork Printed in the US