And the coast of California. Bring it up in Google Earth and look at it from the area of Oxnard/Thousand Oaks down through Huntington Beach, the shape on the screenshot map is pretty close (still exaggerated in some places) to the actual coast line. It even has the Marina just north of the airport which in real life is Marina Del Rey just north of LAX.
The island appears to be based closely on the shape of Catalina Island as well.