The Undersea Trilogy is a series of three science fiction novels by American writers Frederik Pohl and Jack Williamson. The novels were first published by Gnome Press beginning in 1954. The novels were collected in a single omnibus volume published by Baen Books in 1992. The story takes place in and around the United States Sub-Sea Academy and the underwater country of Marinia. The hero of the stories is cadet Jim Eden of the Sub-Sea Academy. Source: Wikipedia (en)