The Intertidal Zone is an unpublished series of educational comic books written and illustrated by Stephen Hillenburg in 1984. The comics were instrumental to his later creation of SpongeBob SquarePants. Many of the show's ideas and characters originated in the comics.
Stephen Hillenburg made The Intertidal Zone in the mid-1980s to teach children about different sea creatures. He worked as a marine science educator at the Ocean Institute in Dana Point, California. While working on Rocko's Modern Life, Martin Olson found Hillenburg's comics and liked them. He suggested that Hillenburg develop The Intertidal Zone into a cartoon series, which became SpongeBoy Ahoy! (later retitled SpongeBob SquarePants).
Hillenburg was interviewed about the comics for SpongeBob Comics No. 1. He said, "I drew it while teaching at what is now called the Ocean Institute, to help explain the life of organisms living in tide pools along the Southern California coast in an entertaining way." He named Robert Crumb and Paul Driessen as influences on the visual style of the comics.
The comics were co-hosted by two sea creatures: a shrimp named Rocky and Bob the Sponge, a very early version of SpongeBob. Each issue featured ocean facts and illustrations of tide pool creatures. Starfish, snails, scallops, and anemones were some of the sea creatures that appeared.
- The Intertidal Zone is mentioned in the "General Trivia" for SpongeBob SquarePants on Amazon Video. It mistakenly states that Hillenburg drew the comics in college; he actually made them while teaching at the Ocean Institute.