First appearance of Fonzie's cousin, Chachi Arcola.
Many fans agree that the show's quality deteriorated after the three-part "Hollywood", where Fonzie jumps a shark while water-skiing. Today, when a show takes a sharp drop in quality, it's said to "jump the shark".
The inspiration for Fonzie's jump over the shark was the TV Special, "Evel Knievel's Death Defiers", which premiered on January 31, 1977. Knievel severely injured himself in a practice jump over a swimming pool, which was to be filled with sharks.
Lorne Greene appears uncredited in his costume as Ben Cartwright from "Bonanza" (1959).