How to Choose a Twin Fin Surfboard

How to Choose a Twin Fin

For many surfers who have spent most of their life using high-performance shortboard thrusters and quads, it is common to feel a certain saturation after so much time using the same style of board and to end up experiencing the same sensations while surfing for so long.

But what should you do to seek new sensations without sacrificing agility and quick responses while surfing?

The answer has existed since the 1970s and 1980s: twin fin surfboards!

What's the difference between a thruster and a twin fin board?

If we compare two identical boards, with the same outline, rocker and bottom, one with a thruster configuration and the other with a twin fin board, the thruster has the same size fins, which provides a slightly more predictable and familiar direction change and navigation on the wave.

The twin fin has much larger front fins positioned further back from where the front fins of a thruster typically are. This factor makes them usually well under the surfer’s back foot, making him feel the board’s tail a bit more fixed and with more drive (ability to maintain speed during direction changes) because of the larger fins and placement.

Differences between classic and modern twin fin boards

So, what factors determine if a twin fin board is classic or modern?

To make this explanation easier, we will use an image of our twin fin board models in order from most classic to most performance.


The easiest factor to observe is the outline design, boards with a more classic feel will have a smaller size and a more filled and parallel outline, reminiscent of the 70’s fish models.

Our Curvalicious and Classic Twin models are twin fin fish boards that have a wide tail and outline. Wide boards are great for surfing weak, slow, and full waves because the surfer’s foot is further from the edge of the board. In waves with these characteristics, where the surfer can’t generate much speed on narrow boards with less floatation, the rail tends to dive more into the water and therefore hit the heel or foot of the surfer, resulting in the famous expression “catching the rail”. On boards with more floatation and wider outlines, this occurs less.

On the other hand, boards with narrower outlines and tails (Butter Biscuit, Duo Diamond and ’80s Twin) are better in stronger and hollow waves because they have a faster response time than boards with wider tails.


Rocker (bottom curve) is one of the most important factors of a surfboard that often goes unnoticed among surfers. The bottom of the board is in contact with the wave surface at all times.

The higher the rocker, the better the board will perform in hollow waves, avoiding it from diving in on the nose when returning from maneuvers in critical wave areas. However, in fat waves, a more pronounced rocker does not generate as much speed as a straighter rocker when doing vertical “pumps” (going up and down) down the wave wall. This is because straighter rockers generate less turbulence in the water passing under the board compared to more pronounced rockers.

In the image above, the models on the left (classic) have less rocker, and the ones on the right (modern) have more rocker.


Volume is the measurement that defines the flotation capacity of the board. In boards designed for weaker waves, it is necessary to increase the volume to better support the weight of the surfer in waves with less power. In waves with more power, too much floatation takes away the sensitivity of the board because the surfer is too high above the surface.

For performance twin fin models, which will be used in wave conditions more similar to what is used in conventional thruster boards, the ideal is to keep the same size as the surfer’s everyday board, perhaps reducing it by 1 to 2 inches, and keeping the same volume or adding up to 1 2 liters.

For more classic twin-fin models, such as the retro Curvalicious and Classic Twin, or even the Butter Biscuit, which is a mid-way between classic and performance, developed for surfing fat and weak wave, it is highly recommended to use them 3 to 5 inches smaller than the surfer’s everyday board and 2 to 5 liters more in volume.

Keel fin and upright twin fin

There are two styles of fin for twin fin boards, the keel fin, which is used on fish boards with a wide tail providing a more linear surf, with a lot of drive and a bit less agility, and the upright twin fin, which is more agile for changing direction and performing maneuvers as they are used on boards with narrower tails where the keel fin would not be advised.

Surfboard with PU (Polyurethane) or EPS/XPS foam?

Surfboards with PU (Polyurethane) foam are laminated using Polyester resin, while surfboards with EPS (Expanded Polystyrene) and XPS (Extruded Polystyrene) foams are laminated using Epoxy resin.

For an authentic experience in classic surfboards, it is advisable to use PU foam as it is heavier and more predictable underfoot, this weight will contribute even more to a relaxed and classic surf. EPS/XPS foams are less dense and lighter than PU foam, which creates agile and lively boards, they are a good option for high performance models and work well in glassy conditions.

Where to buy a Twin Fin?

When ordering your twin fin, it is always advisable to talk to the shaper so that he can develop the board according to your body type and surfing level. We at 1974 Surfboards would be happy to help in this regard, just get in touch.


Want a twin fin that’s easy to catch waves with, has lots of drive, and speed, and is good for relaxed surfing in weak and fat waves?

Choose one of our retro fish models, Classic Twin or Curvalicious.

Would you like a twin fin that works well in smaller waves but can handle a rougher sea?

We recommend the Butter Biscuit.

Looking for a twin fin board that resembles the agility and response of a high performance board?

Choose the ’80s Twin or Duo Diamond.

Do you still have questions? Contact our shaper and have all your doubts cleared.

Contact us.

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