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 underwater dome city called Marinia. The hero of the stories is cadet Jim Eden of the Sub-Sea Academy. Source: Wikipedia (en)