Rough molded foam core that comes in different basic designs and rockers depending on the length and type of surfboard being shaped. Usually made from polyurethane foam.
The lateral curve of the bottom of the board as it runs from rail to rail. Can be concave or convex (vee bottom).
A type of super-strong fiber, soakable in resin, which is occasionally laid in strips along the length of a board during glassing to help prevent creasing.
The channel surfboard bottom consists of flat planes that are designed in a concave configuration. Since the channels sit side by side the water is not being compressed as it is in a full concave, and each channel propel water down the back underbelly of the surfboard and convert this into forward thrust. Longer and deeper channels give a more pronounced effect.
The main purpose of concave is to channel the water flow down the length of the surfboard. This channeling of the water along the center of the board and out through the tail adds more lift and responsiveness to the surfboard. Concaves are a very important design feature and can cause a board to track swiftly and improve tail responsiveness for critical turns.
The effect that causes water flow to be slowed or disrupted as it passes along a surfboard’s surfaces. Controlled drag is an essential requirement of surfboard design.
Type of plastic resin used by some manufacturers in place of polyester resin. Usually an epoxy-user also uses a polystyrene blank, which can be badly affected by polyester resins. Known for its durability.
Expanded Polystyrene. A type of foam also known as styrofoam or bead foam. Polystyrene beads are expanded by steam in a mold with desired density determined by quantity of beads expanded within that mold.
The distribution of foam from nose to tail on a surfboard. For the board to flow correctly, it must be evenly balanced through the shape. If there is excessive foam left in the nose, center, or tail, it will create uneven flow and cause the surfboard to be unbalanced.
The most common type of foam used in surfboard manufacturing. Usually employed together with polyester resin.
The perimeter of the board. There are several different main types of rails which all produce a different effect. Soft and rounded rails make the board slower but easier to handle. Down rails (where the rail comes to an edge toward the bottom of the board) increases speed but makes the board more difficult to turn. Sharper rails promote quick turns but don’t carry momentum as well as fuller rails.
The effect that allows water flow to be accelerated as it passes along a surfboard’s surfaces. Release is altered through tail rocker, outline curves, trailing fin edges, and through bottom features, such as concaves and channels. Controlled release (along with its opposite, drag) is essential to successful surfboard design.
Rocker is the curve of your surfboard from nose to tail. It can be broken down into different sections such as nose rocker, tail rocker, and center. It is the single most important aspect of your surfboard.
The back section of the board. Tail width is measured at a right angle to the board’s stringer, one foot up from the end. Increased tail width means greater speed, especially in smaller surf, but less control; narrower tails don’t maneuver as well, but adhere better to the wave face and are ideal for big-wave boards and tuberiding. Types include swallow, pin, rounded-pin, bat, square, thumb, diamond, and asymmetrical.
The opposite of concave, vee is used to loosen up the tail at high speeds by increasing the rocker at the rail line, making it easier to lean on edge and turn.
Check out the 2011 Surfboard Buyer’s Guide here.