Stumpy, blunt-nosed, two-finned surfboard design invented by San Diego kneeboarder Steve Lis in 1967, featuring low rocker and a split tail, and later adapted for stand-up surfing; San Diego surfers Jeff Ching and Danny Disell were among the first to try their hands at riding the fish while standing rather than kneeling.

While the fish was recognized as a small-wave speed machine—Jim Blears of Hawaii used a 5' 10" fish to win the 1972 World Championships, held in sloppy waist-high surf in San Diego; runner-up David Nuuhiwa also rode one—the stand-up versions of the boards were nearly impossible to control in waves over four feet, so they never gained widespread popularity. In 1976, however, Hawaii's Reno Abellira took a fish to Australia, where it was closely inspected by future world champion Mark Richards, who modified the design the following year to produce a version of the twin-fin that became a surf world best-seller.

In the mid-'90s, a three-fin, small-wave board design—shorter, wider, and thicker than the average tri-fin, buoyed by the popularity of Lost Surfboard's video 5'5" x 19 1/4"—was labeled a "fish," and though it had little in common with the Lis design, it nevertheless helped spark a renewed interest in Lis' original fish shapes.

By 2012, nearly every major boardmaker had a user-friendly and modernized derivative of the fish shape in their product line, and many style-conscious top pros rode them regularly in surf videos, including Rob Machado (The Drifter, 2009), Dave Rastovich (Castles in the Sky, 2010) and Craig Anderson (Innersection, 2010).