What's the Difference, Fin Setups?
This is a question I get often and one I see in groups and forums a lot. Most times I see terrible answers, like "its just personal preference surf what you like". Which there is some preference, but there's more to it. Way more. Fin setups are designed to act in certain ways, for certain boards, and certain conditions. Let's jumped into just the basics of each fin setup design.
Single Fin setup
While we see these mainly on 7'0" and up boards, they are a versatile fin setup. They have been adapted to work on a wide range of surf. The fin is located midline and has a very neutral turning characteristic. They have less drag and thus produce good speed. However they have more drawn out turns.
Twin (2) Fin setup
Often scene on Retro Fish designs, the twin fin allows more maneuverability and speed than a single fin. Placement are near the rail. This allows more hold and control in turns than the single fin. They can feel skatey and can be more difficult to control in larger more powerful surf.
Thruster (3) Fin setup
This design came out of the slide that was felt in the twin fin setup. The third, rear, or trailer fin (whichever you'd like to call) adds stability. It also offers more maneuverability than the twin fin. However the trailer fin creates drag, which aids in control but also adds to slow the board. Thrusters are ideal for more punchy, powerful surf where speed is not a issue but control is more important.
This design was created to help with the control and stability of the single fin. It will help in turning and keeping the board from sliding. But once again will add more drag and slow the board.
Quad (4) Fin setup
Trying to combine the loose turning characteristics of the twin with the control of the thruster, the quad was born. It generates speed and sharp turns. Provides more hold than a twin, faster than a thruster due to no trailer fin creating a lot of turbulence and drag. A great setup allowing speed, control, and drive.
These are just the basics of the setups. A lot goes into how these all will perform. Such as fin size, a big fin template will give more hold and create more drag. Which is good if you're surfing bigger punchy waves where you're looking to control the speed of the wave. Or placement of these will effect performance. Where the cluster is placed on the board, or how tight the cluster is. And of course board design comes into play. A board that is narrower in design will generate less speed, but can offer more control, than a wider design board. Think Gun Vs setup down shortboard.