The film opens in medias res with vacationer Wally Walrus beating Woody Woodpecker into submission on a beach boardwalk. Wally explains to the gathered crowd what happened earlier to provoke his anger:
Wally decides to go to the beach to relax, but is constantly disturbed by surfer Woody. Returning to the present, Wally ties Woody to an anchor and hurls him into the ocean. The rope snags on the pier, demolishing first the pier and then the entire marina. The cartoon ends with Woody swimming away toward the horizon, pursued by Wally, and both of them pursued by the other beachgoers.
The Beach Nut marked the debut of Woody Woodpecker's first steady foil, Wally Walrus. Voiced by actor Hans Conried, Wally became Woody's primary arch enemy until 1948, before being more or less replaced with Buzz Buzzard in Wet Blanket Policy.