On page 1, to the left of the inker credit for Barbara Kaalberg, there is a stray "B" floating over the trimaran! Looks like it is probably an extra B left loose during the arrangement of Barbara's name in the credits.

Carlos explains to the Mariner that he is from an underwater civilization of human survivors called the Foundation. It is located in the submerged ruins of Washington D.C.

On page 2, the book that records the history of the Foundation's work has a drawing of a figure looking similar to the Gill-man from the Creature From the Black Lagoon movies.

The Mariner is able to talk underwater.

The Foundation police wear what appear to be old football helmets!

On page 9, Leviathan threatens to use a spikefish on Alannah, saying the venom from its quills will rot and decay her flesh upon contact. While spikefish are real world creatures, they do not have such venom. The fish seen here may be another evolutionary or genetically engineered aberration.

On page 17 the Mariner seems to confirm he has no actual name.

The Children of Leviathan have painted slogans on the side of their captured submersible vessel. "The end of all creatures of flesh" is from the Bible's Book of Genesis 6:13 as seen painted on the front of the vessel. On another side is painted "Learn to swim."

On page 25, a Foundation police officer wears old political buttons with slogans IKE and DOLE 96. IKE refers to Dwight D. Eisenhower, known as Ike, 34th president of the United States. DOLE 96 refers to the 1996 presidential campaign of Bob Dole, who failed to unseat the 42nd U.S. president, Bill Clinton.