Greenough 4A
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 Fin
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.
Form | Medium profile, full base coupled with a tapering & moderately flexible tip
Function | A fin that will hold when you need it to and release when the time is right
Feel | Neutral-positive, perfectly-balanced, a fin that will drive off the bottom, and have an acute responsiveness through arcing turns
Overall | Versatile - designed for all board shapes and surf conditions
Specifications
The Designer
George Greenough
Santa Barbara, California
Widely considered the father of the modern high-performance fin. His designs revolutionized how surfers think about flex, rake, and hydrodynamic flow. The Greenough 4A is the culmination of decades of refinement — a fin that balances drive, hold, and release in a way that feels intuitive in every condition.
Why Volan?
Volan is a woven fiberglass cloth laid by hand and finished with a resin that cures to a warm amber tint. It flexes differently than solid fiberglass — more spring, more life, more feel through turns. Where solid glass is stiff and direct, volan breathes with the wave.
The hand-laid process means each fin has subtle texture and character. It's heavier, which adds momentum through flat sections. Surfers who ride volan describe it as "warmer" — the fin does more of the work, trimming and holding without demanding constant input.
Shop the Greenough 4A Volan ›
Greenough 4A
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.