Those shots of Fabian, Peter Brown and Tab Hunter--photographed from mid-chest up--riding their surfboards were actually shot on a sound stage at Columbia Studios. The actors balanced on Radio Flyer wagons in front of a rear-projection screen showing ocean waves. Assistants then sprayed them with water while maneuvering the wagons to give the desired effect.
The Tab Hunter character "Steamer Lane" was named for the world-class surfing spot in Santa Cruz, Calif. Surfing pioneer Jack O'Neill tested and improved his invention, the neoprene wetsuit, at Steamer Lane in the '50s. The O'Neill Coldwater Classic competition has attracted the world's top surfers to The Lane annually since 1987, with a $425,000 prize purse in 2012.
The first feature film directed by TV-veteran Don Taylor. When his mother died during filming, Columbia brought in Phil Karlson to direct a few scenes (uncredited) in Taylor's absence. According to Tab Hunter's autobiography, Karlson directed the scene in which Hunter assures his future mother-in-law that he's not a beach bum but rather a hard-working citizen. Producer Art Napoleon also directed some scenes uncredited.
The Waimea footage in the movie was actually shot by the Napoleons, who traveled to Hawaii specifically to capture surfers taking on the giant waves. A series of weather conditions had come together to produce one of the longest uninterrupted periods of big waves in recent memory in late 1962 through March 1963. The Napoleons, equipped with these spectacular shots, went back to California and wrote the script around them.
Despite pulling Jan and Dean from the movie, Columbia had no problem keeping in their closing song, "Ride the Wild Surf", co-written by Jan, Beach Boy Brian Wilson, and famous surf lyricist Roger Christian. The song went to #16 on Billboard's Top 100 on October 31, 1964,
The night after the first day of surfing, Tab Hunter comes running into the cottage to tell the other two guys he has discovered who the woman on horseback is. When describing her he says, "The guy just drove up to say hi." But the woman shot at him with a shotgun and, " the shot blew the skegs clean off the two boards he had on top." Skegs are the fins on the bottom of the boards.
In the era prior to modern of film making, it was often cheaper to film night scenes during the day by turning down the exposure on the camera. The technique was used for many old films and works when attention is focused on the actors. The problem arises when backgrounds appear brighter than they would at night ... and if such areas occur, they are usually attempted to be covered with foliage. In this film a completely different giveaway occurs, when Jody and Brie take a walk together right after the spear gun, target shooting contest ... as they walk down the darkened path, you can hear birds chirping. If this was night, the birds would be asleep. Birds begin chirping right before dawn and do not stop until the sun sets.