Surf

Intro

The wrong surfboard is the most common reason people struggle to improve. A board that is too small makes paddling exhausting and catching waves almost impossible. A board that is too big for your ability and waves feels like a barge when you try to turn. And the language of surfboards does not help: litres, rocker, foil, rails, five-fin boxes, 6'2" × 19¼" × 2⅜".

This guide explains what all of that means and gives a practical method to choose a board. It draws on guides from Surfer Today, Board Cave, Swellnet and Rapture Surfcamps, linked at the bottom. No formula replaces advice from a shaper or a good surf shop that knows your local waves, but you will go in knowing what to ask.

Reading a surfboard's dimensions

Surfboard sizes are usually given in feet and inches:

• Length, for example 6'2" (six feet two inches, about 188 cm). Longer boards paddle faster and catch waves earlier. Shorter boards turn more easily.
• Width, measured at the widest point, for example 19¼". Wider boards are more stable.
• Thickness, at the thickest point, for example 2⅜". Thicker boards float more.
• Volume, in litres. This combines length, width and thickness, plus how the foam is distributed, into one number. Volume is the most useful number for comparing boards of different shapes.

Volume: the number that matters most

Volume decides how well a board floats you, which decides how easily you paddle and catch waves. Too little and you sink, paddle slowly and miss waves. Too much and the board is hard to sink into a turn or duck-dive.

The Guild Factor formula

A widely used starting point, described by Surfer Today, is:

Your weight in kg × Guild Factor = recommended volume in litres

The Guild Factor depends on your level:

Surfer Today adds that epoxy and EPS foam boards float more than traditional polyurethane boards, so you can take off about 2–3 litres from the result.

Quick volume table

We used the formula with the middle of each range (beginner at the lower limit, so treat those as a minimum):

Be honest about your level. Most surfers overestimate it. If you surf a few times a year, you are in the "casual" band even if you have surfed for a decade. Fitness, age, cold water with a thick wetsuit and weak waves all push you towards more volume. For true beginners, more is better: most surf schools start people on long, soft boards with far more volume than the formula's minimum.

One caution: the formula is a guideline. Surfer Today's own chart does not match its formula perfectly in every row, and two boards with the same volume can feel very different depending on where that volume sits.

The main types of surfboard

Lengths are typical ranges from Board Cave and Rapture Surfcamps, not strict rules. Shapers vary a lot.

Shape: the parts of a board

Outline

The outline is the shape seen from above. A wide, round outline (fish, longboard) is stable and fast in small waves. A narrow, pulled-in outline (shortboard, gun) holds better in steep, powerful waves.

Rocker

Rocker is the curve of the board from nose to tail, seen from the side. Swellnet's shaping explainer describes it as the main factor in how fast a board goes and how easily it turns:

• Flatter rocker paddles faster and goes faster in a straight line, but is harder to turn. Good for small, weak waves.
• More rocker (a "banana" shape) turns tightly and fits into steep, curving waves, but can feel slow in small surf.
• Nose rocker decides how the board meets the water. Too much and it pushes water instead of gliding.
• Tail rocker helps the board release from the water when turning.

Swellnet's rule of thumb: if you are pushing water or cannot turn, you are probably on the wrong rocker.

Rails

The rails are the edges of the board.

• Soft, rounded rails are forgiving and smooth. Common on longboards and beginner boards.
• Hard, sharp rails (especially towards the tail) grip and release water quickly, giving speed and bite in turns. Common on performance shortboards.
• Down rails have the edge low near the bottom for more bite. Boxy rails are fuller and thicker, which adds volume and forgiveness.

Bottom contours

The underside of a board is rarely completely flat. Concave (a slight channel) directs water along the board and adds lift and speed. Vee (a slight V-shape near the tail) helps the board roll from rail to rail. Most modern boards mix these.

Tail shapes

Foil and stringer

Foil is how the thickness is spread from nose to tail. A thin nose and tail with thickness under the chest is a classic performance foil. The stringer is the thin strip of wood running down the middle of most boards, which adds strength and controls flex.

Fins

Fins give the board grip and direction. The setup changes how it rides, as Surfer Today describes:

If your board has five fin boxes, you can experiment with both thruster and quad setups to see which suits your waves.

Construction

• PU/PE (polyurethane foam, polyester resin): the traditional build. Responsive feel, but dings more easily.
• EPS/epoxy: lighter and more buoyant for the same size, and usually stronger. Some surfers find it bouncier in choppy water.
• Soft-top: a foam deck over a stiffer core. Safe, durable and ideal for learning.

How to buy the right board: a step-by-step method

1. Be honest about your level and how often you surf. This matters more than anything.
2. Calculate your volume with the formula above, then add more if you are a beginner, surf rarely, are older, or surf weak waves in a thick wetsuit.
3. Think about your usual waves, not the best day of the year. Small and mushy? Go wider, flatter and fuller. Powerful and steep? Narrower, more rocker.
4. Pick a board type from the table above that matches your level and waves.
5. Check the volume of the specific model in your chosen length. Most shapers publish litres for every size.
6. Ask a local shaper or shop. Tell them your weight, level, how often you surf and where. They know your waves.
7. Consider second-hand for your first boards. You will probably move through a few as you improve.
8. Plan for a quiver later. Many surfers end up with two boards: one for small days, one for good days.

Common mistakes

• Going too small too soon. The most common mistake. A shortboard looks great in the shop, but if you cannot catch waves on it you will not improve.
• Judging by length alone. A 6'0" fish and a 6'0" shortboard can differ by many litres. Compare volume.
• Buying for perfect waves. Buy for the waves you actually surf most of the time.

Sources

• Surfer Today: The surfboard volume calculator
• Surfer Today: Surfboard design, length, width, thickness, rocker and tail
• Surfer Today: How does surfboard rocker affect wave riding?
• Surfer Today: Surfboard fin setups, single, twin, thruster, quad and five-fin
• Surfer Today: Thruster, the three-fin design by Simon Anderson
• Swellnet: Boarding School, rocker
• Board Cave: Types of surfboards
• Rapture Surfcamps: A guide to different types of surfboards