Guide to Fin Selection

FCS thruster and quad sets are categorised by size. Each size category has an optimum weight range that can be used as a guide when choosing a fin:

  • XSOptimum Weight Range
    under 120lbs / under 55kg
  • SOptimum Weight Range
    120-155lbs / 55-70kg
  • MOptimum Weight Range
    140-175lbs / 65-80kg
  • LOptimum Weight Range
    165-200lbs / 75-90kg
  • XLOptimum Weight Range
    over 190lbs / over 85kg
  • SpecialisedFor specific surfboard designs or as specialised fins

Example of the fin ratings system

Fin Example

All FCS thruster, quad and quad rear fins come with fin ratings. These fin ratings provide the drive, pivot and hold characteristics of each individual fin set and are based on elements such as area, base length, sweep, depth, material and template.

FCS provides these fin ratings as a guide to individual fin performance. They can also be used as a reference when choosing a fin for specific performance requirements.

Fins are rated relative only to the fins within each size category and are not comparable across other sizes. For example, the drive rating on a medium fin can only be compared to the drive rating on other medium fins.

Performance Ratings



Drive provides forward acceleration and helps maintain speed through turns.

The amount of drive produced by a fin is directly influenced by the base length, material and the total surface area.

Put simply; a larger fin with a longer base will offer more drive.

white less drive
black more drive



Pivot refers to the length of the turning arc.

Pivot is influenced by the sweep angle or rake, the foil and the depth of the fin.

Fins with less sweep angle will turn in a tighter arc; fins with more sweep angle will turn in a longer arc.

white tight arc
black long arc



Hold is defined as the binding of the board to the wave.

Hold is determined by flex and the overall fin template.

Fins with more hold prevent the board sliding through turns, less hold allows the board to easily break free from the wave during turns; this is often referred to as ‘release’.

white less hold
black more hold