The Greenough 4-A Single Fin is the most iconic, functional and versatile single fin available, because it works extremely well on just about every type of surfboard. The 4-A has been True Ames' bread and butter for over 40 years now, and it is still the most popular single fin design there is due to it's all-around and well-balanced performance.
| SIZE | HEIGHT | BASE | AREA |
|---|---|---|---|
| 6.5” | 6.49” | 5.42” | 22.86”² |
| 7.0” | 7.09” | 5.67” | 24.89”² |
| 7.5” | 7.55” | 5.95” | 26.86”² |
| 8.0” | 8.11” | 6.09” | 28.85”² |
| 8.5” | 8.51” | 6.42” | 32.19”² |
| 9.0” | 9.14” | 6.93” | 36.13”² |
| 9.75” | 9.71” | 7.09” | 39.93”² |
| 10.0” | 10.08” | 7.42” | 43.85”² |
| 10.5” | 10.63” | 7.91” | 48.44”² |
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.
Whether you’re new to exploring the benefits of experimenting with new fins, or you’re a seasoned veteran... our fin guide will break down the basics, as well as some of the more complicated aspects of fin design to help ensure that you find the right setup for your board. Learn about different fin types, terminology, as well as some of the crucial factors that ultimately determine feel and performance here.
