What a Twinzer Actually Is
The twinzer is Wil Jobson's 1988 design — a four-fin setup where two small fins (canards) sit forward and outboard of two larger rear fins. It's not a quad. It's not a twin with trailers. The geometry is fundamentally different: the canards are placed ahead of the main fins, not behind them.
The name comes from aerospace. A canard is a small forward wing on a fighter jet — the Eurofighter Typhoon, the Gripen, Burt Rutan's designs. In aviation, the canard pre-conditions airflow hitting the main wing, letting it operate more efficiently at higher angles of attack. Jobson applied the same principle to water.
It worked. Martin Potter won the 1989 world title riding a twinzer. That's not trivia — it's the only time a non-thruster fin setup has won a world title since Simon Anderson's thruster took over in 1981. Potter's boards had speed and hold that nobody expected from a non-three-fin design. The surf world mostly shrugged and went back to thrusters anyway, which is a shame, because the twinzer solves real problems that thrusters create.
How Canards Actually Work
Most fin marketing describes canards as "adding speed" or "loosening the tail." That's not wrong, but it's not useful either. Here's what's actually happening hydrodynamically.
Pressure Redirection
The canard generates lift (lateral force) as water flows over its foil. This redirected water hits the main fin's foil side — the low-pressure, power-generating face — at a more favorable angle. The main fin gets pre-loaded flow instead of having to do all the work of redirecting raw water on its own. Think of it like a turbocharger for the main fin: the energy to redirect flow has already been partially spent by the canard.
Anti-Ventilation
Ventilation is what happens when air gets sucked down the fin surface from the water's surface, breaking the boundary layer and causing the fin to lose grip suddenly. It's the underwater equivalent of a stall. The canard sits forward and slightly outboard, creating a pressure zone at the base of the main fin that resists air intrusion. This is why twinzers hold through sections where a twin fin would slide out — the canard is acting as an anti-ventilation fence.
Effective Aspect Ratio Increase
Here's the subtlest and most important effect. The canard's wake creates a virtual extension of the main fin's effective span. In aviation, this is called the "endplate effect" — the canard's pressure field makes the main fin behave as though it has a higher aspect ratio than its physical dimensions suggest. Higher aspect ratio means more lift per unit of drag. That's why twinzers feel fast: the main fins are generating more drive with less resistance than they would alone.
Higher Angle of Attack Before Stall
All three effects combine to let the main fin operate at higher angles of attack before stalling. In plain terms: you can push the board harder into a turn before the fins let go. A thruster achieves this with a center fin (which adds drag). A twinzer achieves it with canards (which add less drag because they're smaller and forward-mounted). The tradeoff is that a thruster's center fin provides a more linear, predictable hold curve, while a twinzer's hold curve has a sharper breakaway point — it holds, holds, holds, then releases more suddenly.
This is still somewhat debated in shaping circles. The pressure redirection and anti-ventilation effects are well-understood and measurable. The aspect ratio claims are harder to isolate in turbulent, aerated surf conditions. But the practical result is clear enough: twinzers hold better than twins and feel faster than thrusters.
Cant Angle on Canards
Cant is the angle of the fin relative to the bottom of the board, measured from vertical. A fin at 0° cant is perfectly perpendicular to the board's bottom. More cant means the fin is tilted outward, toward the rail.
In a twinzer, the canard always has more cant than the main fin. This is fundamental to the design. Jobson's original spec was 9-11° on the canard and 2-4° on the main fin. The differential matters: it's what creates the pressure gradient that feeds flow onto the main fin's working face.
True Ames Cant Options
True Ames canards come in three cant options: 0°, 4°, and 9°. Here's how to think about them:
- 0° cant: The canard is vertical. Minimal pressure redirection onto the main fin. This makes the setup feel most like a pure twin — loose, skatey, less hold. Only choose this if you want maximum looseness and are comfortable with the board sliding.
- 4° cant: A moderate split. Adds some bite on rail without fully committing to the twinzer effect. Good for smaller, softer waves where you want a bit of extra hold but don't need the full Jobson geometry.
- 9° cant: The original Jobson spec. Full twinzer behavior — maximum pressure feed to the main fin, maximum anti-ventilation effect. This is the sweet spot for most surfers and most conditions. If you're not sure, start here.
The total cant differential (canard cant minus main fin cant) is what determines the twinzer effect's intensity. With a main fin at 2-4° and a canard at 9°, you're getting 5-7° of differential — right in the range Jobson intended. Dropping the canard to 0° with a 3° main fin gives you a -3° differential, which effectively cancels the twinzer geometry and gives you a four-fin setup that behaves more like a twin plus stabilizers.
Canard Size Matters
The ratio between canard area and main fin area determines the character of the setup. This isn't a minor tuning variable — it's the biggest single factor in how a twinzer rides.
Smaller Canards (5.5-6.0 sq in)
A smaller canard generates less pressure redirection and less anti-ventilation effect. The setup rides closer to a pure twin: looser, more pivot, less drive through the bottom turn. The Pavel twinzer canard at 5.97 sq in is the smallest in the True Ames lineup. If you love how a twin feels but want just a bit more hold in bigger surf, a small canard is the move.
Larger Canards (7.5-8.0 sq in)
A larger canard does more work: more flow redirection, more anti-ventilation, more drive. The setup feels more planted, more like a thruster's hold characteristics but without the center-fin drag. The standard TA Twinzer canard at 7.77 sq in is the benchmark here.
The Overlap Problem
If the canard is too large relative to the main fin, or positioned with too much lateral overlap, the canard's wake can interfere with the main fin's leading edge. Instead of feeding clean pre-conditioned flow, the canard dumps turbulent wake directly onto the main fin. This causes intermittent stalling — the board feels inconsistent, gripping then releasing unpredictably. If your twinzer setup feels "twitchy" at speed, the canard-main overlap is the first thing to investigate. Most production twinzer boxes get this right, but it's worth knowing if you're experimenting with placement.
The True Ames Twinzer Lineup
True Ames is the primary manufacturer keeping the twinzer alive in production. Here's each template with actual measurements and honest assessments of who they're for.
TA Twinzer
Canard: 7.77 sq in | Rear fin: 19.32 sq in
The standard. This is the template closest to Jobson's original geometry. The 7.77 sq in canard is the largest in the lineup (tied with the Lovelace), and the 19.32 sq in rear fin provides the most hold. If you're riding a performance shortboard in overhead-plus surf and want maximum drive and hold from a twinzer, this is the setup. It's the least "twin-like" option — it'll feel planted and directional, closer to a thruster's stability curve. Not the right choice if you want looseness.
Mandala (Manny Caro)
Canard: 6.07 sq in | Rear fin: 16.79 sq in
Manny Caro designed this template around golden-ratio proportions — the canard-to-rear-fin area ratio is approximately 1:2.77, close to the golden ratio's inverse. Whether that's meaningful hydrodynamics or aesthetic philosophy is debatable, but the result speaks for itself: the Mandala is the most balanced twinzer in the lineup. The 6.07 sq in canard is small enough to keep things lively while the 16.79 sq in rear fin provides moderate hold. This is the twinzer for surfers who want the best of both worlds — twin-fin looseness with twinzer hold. Works beautifully in fish and retro shapes from waist-high to head-high.
Pavel
Canard: 5.97 sq in | Rear fin: 17.82 sq in
The Pavel has the smallest canard in the lineup at 5.97 sq in, paired with a mid-sized 17.82 sq in rear fin. This gives it the most pivot and the least canard influence — it's the closest thing to a twin fin with training wheels. The rear fins do most of the work; the canards provide just enough pressure feed and anti-ventilation to prevent the tail from washing out in critical sections. This is the twinzer for committed twin-fin riders who want a safety net, not a personality change. Excellent in down-the-line fish and wider-tailed retro boards.
Lovelace
Canard: 7.75 sq in | Rear fin: 18.85 sq in
The Lovelace is a tribute to Richard Kenvin and the Hydrodynamica school of fin design. The canard area (7.75 sq in) is nearly identical to the TA Twinzer's, but the rear fin is slightly smaller at 18.85 sq in (vs 19.32). The result is a setup that has the same canard authority as the TA but releases slightly more easily off the top. The difference is subtle — we're talking about 0.47 sq in less rear fin area — but it's noticeable if you're used to one or the other. A solid choice for performance shortboards where you want twinzer hold with a bit more tail freedom.
Lovelace FM (For Midlengths)
Canard: 3.70 sq in | Rear fin: 22.46 sq in
This is the oddball, and it's fascinating. The Lovelace FM was designed specifically for midlengths (7'0"+), with an unconventional approach: a tiny 3.70 sq in canard paired with a large 22.46 sq in rear fin. The canard-to-rear ratio (1:6.07) is radically different from any other twinzer template. On a midlength, you don't need the canard doing heavy lifting — the board's extra length and volume provide inherent hold. What you need is a bit of flow pre-conditioning to keep the larger rear fins working efficiently through longer, drawn-out turns. The FM's small canards deliver exactly that. The rear fins are positioned and sized to handle the different trim lines of a midlength. If you're riding a 7'0"+ twin-fin midlength, this is probably the only twinzer template designed with your board in mind.
How to Choose
Forget analysis paralysis. Match your board to a template:
Fish or Retro Twin
You already like how twins feel. You want a bit more hold without losing the character. Go Mandala for balanced performance or Pavel if you want to stay as close to pure twin feel as possible. Run the canards at 9° cant.
Performance Shortboard
You're coming from a thruster and want more speed without sacrificing hold. Go TA Twinzer for maximum hold or Lovelace if you want slightly more release off the top. These are the templates designed for boards with narrower tails and more rocker. Canards at 9° cant.
Midlength (7'0"+)
Only one real option: the Lovelace FM. Its tiny canard and large rear fin are proportioned for the different hydrodynamics of a longer board. Trying to force a shortboard twinzer template onto a midlength will give you too much canard influence and a board that fights you through trim.
Still Not Sure?
Start with the Mandala. It's the most versatile template in the lineup and works across the widest range of board shapes and wave conditions. Pair it with 9° canards and ride it for a month before second-guessing anything. The Mandala is also the easiest to swap from — if you want more hold, move to the TA Twinzer; if you want more looseness, move to the Pavel. It's the center of the twinzer spectrum.