Malibu, California, 1962.Matt 'the Enforcer' Johnson (Jan-Michael Vincent), Jack Barlow (William Katt), and Leroy 'the Masochist' Smith (Gary Busey) are the three best surfers of the beach. On the morning of the South swell Matt is drunk, but he borrows a board from a little boy and succeeds in giving an excellent performance anyway.The three friends usually take their boards for free from Bear (Sam Melville), a man that believes in their success and who owns illegally a shop in a hut on the pier.One day, Jack meets Sally (Patti D'Arbanville), a nice girl from Chicago, in the cafe where she works as a waitress. He takes her to his home, to a frantic and chaotic party which a brawl ensues when a group of party crashers arrive and cause a ruckus.Another time later, Matt, Jack and Leroy go for a trip to Tijuana, Mexico, where Peggy (Lee Purcell), Matt's girlfriend, announces to the group that she is pregnant: she and Matt will have a baby. Matt, Jack, Leroy, Sally and Peggy have a good time, and but get into a barroom brawl at a strip club. They all manage to escape from the local police, but they find their car stripped and broken-into. They manage to replace the stolen tires and return to Malibu.A short time later, the Malibu police make Bear's shop close: the pier will be demolished.Three years later, 1965; The Western Swell.Jack, the most serious of the three, is working as a lifeguard on the beach, and is still with Sally. Matt lives with Peggy and their little daughter; he's the greatest surf champion, but he is always drunk and depressed: he hates being a hero. While drunk, he provokes a road accident in front of the beach and Jack hits him and throws him off the beach.The three friends, as many others, have received the draft notice, and this means being sent to Vietnam... to fight an unpopular war.Bear has gotten rich: he owns a new bright surf shop in downtown Malibu and is about to marry. At his wedding, he speaks to Jack about the importance of friendship: Matt and Jack make peace.The Malibu guys have all to show up at the induction on the same day. In order to dodge the draft, Leroy pretends to be mentally insane, Matt simulates a serious problem in his leg, Waxer (Darrell Fetty) (another friend from the beach) pretends to be homosexual, but he's not believed. Jack doesn't do anything: he probably thinks it's his patriotic duty.Matt and Leroy succeed in avoiding it. Jack and Waxer are drafted into the US Army.In a flash forward to 1968, it is revealed that Waxer has died in Vietnam. Matt now works as a swimming pool lifeguard. He's invited to the premiere of a surf documentary, with some scenes about him. But upon seeing the film, he is disappointed: the film shows how his style has been overcome by a new surf hero, (Gerry Lopez, as himself). Bear has lost all his money, and his wife has left him. Jack comes back home from Vietnam but Sally is not waiting for him. While he was fighting far from home, she married another man, (Steve Kanaly), one of the guys who were at the party in 1962.In the cemetery, in front of Waxer's grave, they remember their dead friend and recall nostalgic memories of the past.Three years later in 1971.Bear has become a drunkard and a homeless, but is still proud of his surfer friends.The greatest swell ever is coming. On the day of its utmost intensity (Big Wednesday) lifeguards warn people to stay off the beach. Matt, Jack and Leroy meet on the shore and go surfing one last time for old times sake. So does Lopez, the new surfer, who looks at them with admiration and respect. They are still great, but Matt slips off his board and seems to disappear under a gigantic wave. When he reappears, on the beach, he and his two friends are ready to acknowledge the supremacy of Lopez, the new champion surfer. The film ends with Matt, Jack and Leroy leaving the beach for the last time and leaving them their past and their youth which is no more.