Fin Basics

Surfboard fins are found underneath every surfboard, usually toward the bottom back end. Surf fins are an essential part of a surfboard and play a number of important roles.

Fins are the keel of a surfboard (the positioning of your body weight, using your feet, is like your steering wheel). Without fins you would have no control of the direction of the surfboard. Fins allow you to turn left and right and keep you from falling off the face of the wave. Some call this the ability to hold on to or grab a wave.

Friction is created between the fins and the surf when a surfer pushes down with his/her foot on the back of a surfboard. Pressure from the feet and changes in body placement will cause the board to turn right or left.

The importance of fins in tweaking your ride is lost on many surfers. A fins shape, size, weight, material and placement changes the way the surfboard responds on the wave. Changing out fins can give you a refreshed, more enjoyable ride and make your old board feel different and new again.

Basically, the two extremes are: 1) A board feels looser and control is lost and the board may slide during turns with smaller fins (less sweep, area and length; see Fins Terminology), 2) The control will be greater, with more drive (control through turns), and the ride stiffer with larger more engineered fins (less flex, more sweep), which can help beginners for rides like Macao Beach in the Dominican Republic.