Greenough
The fin designs that changed surfing forever.
Made by True Ames in Goleta, California.
George Greenough studied the caudal fins of tuna, the wings of birds, and decades of wave riding to replace the heavy D-fins of the 1960s with flexible, foiled templates that let boards turn, trim, and fly. His film The Innermost Limits of Pure Fun (1970) directly inspired the shortboard revolution. Every modern fin owes something to his work.
Which fin is right for you?
8 designs in stock. Scroll to explore, or jump from the sidebar.
Start Here
Not sure which Greenough? Start with one of these.
Greenough 4A
The most versatile Greenough fin ever made.
Medium profile with a full base and moderately flexible tip. Holds when you need it, releases when the time is right. Neutral-positive feel with acute responsiveness through arcing turns.
- +Surfers who want one fin that does everything
- +First Greenough fin — the safe pick
- +Any single-fin board from 6'6" to 10'+
Greenough 4A Volan
The 4A in hand-laid volan cloth — worth every penny of the upgrade.
The standard 4A uses 3/8" fiberglass panels — thinner than Greenough originally designed. The Volan uses ~1/2" panels, matching his intent. That difference changes everything: thinner panels concentrate flex at the tip, but the Volan distributes flex through the whole fin — more drive off the bottom, more projection on release. Hand-laid in Santa Barbara with heavier volan cloth (the greenish-tint vintage fiberglass), better weave orientation, and tighter quality control than the machine-made standard. The standard feels responsive but dead through the body. The Volan feels alive the whole way through.
- +Primary single-fin riders who surf most sessions on one fin
- +Hull, egg, and mid-length riders who want more drive
- +4A riders who want flex distributed through the whole fin, not just the tip
- +Equipment-focused surfers — the difference is real and immediate
Greenough Stage-6
Speed fin with windsurf DNA. Stiff leg, active paddle.
Originally rooted in Greenough's windsurf designs. The "stiff leg" cuts through kelp and textured water, while the "active paddle" keeps the board rooted at speed. Same surface area as other fins, but distributed for speed and control. The widest size range in the Greenough line — 5" to 9.75".
- +Surfers who want speed and drive from a unique flex pattern
- +Multiple board quivers — available from shortboard to longboard sizes
- +Mid-lengths and edge boards where speed matters
Speed & Performance
Drive, speed, and power off the bottom.
Greenough High Speed
High-aspect ratio. Airplane-wing design for speed.
One of the truest examples of Greenough's high-aspect ratio fin design — slender like an airplane wing, generating lift while maintaining very low drag. Originally designed for Greenough's "Edge" boards. Volan construction adds a lively flex pattern. Point breaks and down-the-line waves are where this fin shines.
- +Point break and down-the-line surfers
- +Speed and flow over tight turns
- +Edge boards and speed shapes
Greenough Power Glide 45
The Power Blade, refined. More approachable, more flex.
Builds on the Power Blade but refined into a more approachable fin — more rake (32°, appearing to approach 45°), more area, more flex, and softer curves. Designed with Greenough for a wider range of boards and surfers. A more generous turning radius while maintaining the speed and drive of the Power Blade lineage.
- +Surfers who want Power Blade DNA in a more forgiving package
- +Down-the-line surfing with smoother, wider turns
- +Mid-lengths and edge boards in a range of conditions
Classic & Traditional
Original templates for classic longboards.
Greenough Stage III
The original. Classic wave-set template.
Large, upright fin with a wide base and moderate rake. Ample drive with a blend of hold and release for rail-to-rail surfing. True Ames' take on the classic molded Wave-Set fin, now in solid fiberglass. Responsive, loose, and freeing.
- +Classic longboard riders who want hold and release
- +Surfers who want the original Greenough feel
- +Rail-to-rail flow surfing on traditional shapes
Greenough 4C
9.5" classic. Every color.
Single size (9.5") in a huge range of colors — clear, smoke, black, blue, green, purple, red, yellow. A focused Greenough template for longboards. Solid fiberglass with moderate flex.
- +Longboard riders who want a specific color
- +Surfers who know they need a 9.5" fin
- +Classic log styling with Greenough performance
2+1 Setups
Center + side bite combos and trailer fins.
4A 2+1 Combo (FCS)
4A center + FCS side bites. Complete setup.
Full 2+1 package: Greenough 4A center fin with matched FCS side bites. Adds hold and drive through turns while keeping the single-fin trim feel.
- +2+1 riders who want the 4A with matched sides
- +Mid-lengths with FCS side plugs
- +Surfers stepping up from a pure single fin
Power Blade
How a 1960 V-slot experiment became the most advanced single fin ever made.
Read more ›Power Glide 45
Same twist-fin DNA — built for a wider range of boards and surfers.
Read more ›Why the Volan 4A Is Worth It
Thicker panels, hand-laid construction, flex through the whole fin — what $30 actually buys you.
See the Volan 4A ›All Greenough Products
Still not sure?
We carry the full Greenough line at 4051 Judah St in the Outer Sunset. Bring your board.
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