Fin TerminologyUpdated 2 months ago

Below are some explanations of commonly used fin Terminology, including fin characteristics, materials, foil information, and more:

Flex:  How much and how easily a fin bends under pressure before snapping back to its original shape. This characteristic plays a key role in a surfboard's performance, influencing speed, control, and maneuverability.

Depth:  Depth is the distance the fin penetrates into the water. Depth directly relates to hold. The greater the depth, the more hold; the shorter the depth, the more a board will slide and release.

Base:  Base is the length between the leading and trailing edge where the fin meets the board. Base is primarily linked to drive. Fins with a longer base will offer substantially more drive and acceleration.

Sweep/Rake: Sweep is the angle measuring how far the outline of the fin is curved backwards; also referred to as rake. Sweep has a direct influence on pivot. Fins with more sweep produce a longer turning arc, less sweep offers a tighter turning arc.

Cant: refers to the angle at which the fin leans outward from the board when viewed from the back. It influences how responsive and maneuverable the board feels.

Area:  Area is the total surface area of the fin.

Drive: 
- Provides forward acceleration and helps maintain speed through turns
- Influenced by the base length, material, and the total surface area
- Large fin + longer base = more drive; Smaller fin + shorter base = less drive.

Pivot:
- Refers to the length of the turning arc
- Influenced by the sweep angle or rake, the foil, and the depth of the fin.
- Less sweep = tighter arc; more sweep = longer arc.

Release:
- Defined as the fins binding properties to the wave face
- Influenced by centre fin size, sweep angle or rake, and total surface area.
- Smaller centre fin = More Release; Consistent size fins = Less Release

Inside Foil: 
- Rounded leading edge, concave inside face.
- Inside foil increases efficient water flow.
- Adds lift and hold while reducing drag.
- Helps surfers maintain speed through turns.

Flat Foil:
- Even combination of drive, pivot and hold.
- Fast directional changes.
- Preferred by advanced and pro surfers.

50/50 Foil:
- Symmetrical foil is used on centre fins and sometimes quad rears.
- Even water flow creates stability and control.

80/20 + 70/20 Foil:
- Asymmetrical foil typically used for quad rear fins.
- Allows for fast turning sensitivity while still providing stability and control.

Performance Glass (PG): Performance Glass material characteristics and flex pattern are identical to traditional fibreglass fins, offering a stiff base with subtle responsive tip flex, amazing aesthetics, and proven durability. PG fins are the perfect transition fin for surfers moving from fixed fins to the convenience, accuracy, and performance of FCS.

Performance Core Carbon (PCC): Performance Core construction with hand-laid carbon fiber designed to deliver controlled flex and enhanced base stiffness.

Performance Core (PC) + AirCore: Fins with AirCore Technology feature a pressed polyurethane foam core that mimics the geometric foil of the fin. AirCore technology reduces the amount of fiberglass required in the RTM moulding process, making it much lighter while allowing total manipulation of the flex.

Performance Core (PC): Performance Core material and construction is designed to deliver the feeling of a traditional fibreglass fin with the added performance of reduced weight. The RTM (Resin Transfer Moulding) process produces a lightweight fin with remarkable flex, a smooth feel and an impressive aesthetic.

Neo Carbon: Neo Carbon fins are precision molded using long strand carbon and the highest-grade European resin. These fins are super light with a firm ‘spring loaded’ flex. Neo Carbon fins actually help surfers generate speed in smaller conditions via the ‘whipping effect’ that propels you from one turn into the next. 

Neo Glass: Lightweight, moulded fiberglass construction delivers pro-standard performance. The high fiberglass content makes these fins stiff and responsive, and the engineered foils provide a consistent feel in a range of different conditions.

Glass Flex (GF): Glass Flex has been formulated to replicate the flex and memory properties of hand-laid fibreglass. It's advantages over other composite fin materials include stiffness, a more positive flex pattern (nice tip flex, little base flex) and remarkable flex memory. The precision of the injection moulding process ensures the highest accuracy in geometry in each fin produced.

Soft Flex: Soft Flex fins are molded using highly flexible urethane. For this reason, they’re safe, mostly used with softboards, and are ideal for beginners as they gain confidence in the water.