The Greenough 4-A is not only the bread and butter of our collection, but it’s also been the most popular single fin worldwide for decades–and for good reason–its incredible functionality and versatility means it’ll work on just about anything.

The man behind this revolutionary fin is George Greenough, whom the surf world is forever indebted to for his wave-riding performance innovations beginning in the '60s. Greenough ultimately paved the way from traditional logging to more progressive surfing in the pocket through the development of his Velo-Spoon kneeboard designs. To complement his kneeboards, Greenough found inspiration from mother nature for his fin templates through studying the tail fins of tuna–one of the fastest and most maneuverable fish in the ocean. The subsequent high-aspect ratio design he created allowed surfers to place themselves in more critical parts of the wave and execute more radical turns; it truly ushered in a new era of high performance capability.

History lesson aside, the Greenough 4-A is a truly well-balanced fin. Its full base coupled with a tapering, moderately flexible tip provides a solid amount of drive off the bottom, and an acute responsiveness through arcing turns. Designed for both speed generation and spending time surfing in the pocket, the 4-A is a fin that will hold when you need it to and release when the time is right.

• A true all-arounder, the 4-A is one of the most versatile single fins ever designed 
• The larger sizes are great for single fin longboards, while the smaller and medium sizes pair well with mid-lengths, performance single fins, and 2+1’s
• Best of both worlds performance: solid base and width create stability and drive, while the rake and flexible tip enables top-to-bottom turns and maneuverability
• Solid fiberglass construction, flat matte finish