Shape.
Flow. Feel.
A board is a set of design decisions you can stand on. Geometry meets water, speed, and a moving human.
Change one dimension.
Keep a board’s length fixed at 72 inches. Adjust its width and watch the outline change. This is a geometry sketch, not a board-design simulator.
Length-to-width ratio: 3.60
Bounding rectangle: 1440 in²
The rectangle is larger than the actual planform area. Thickness, volume, rocker, and rider are outside this model.
Four places to get curious.
Rails / the edge that meets the water
Compare a rounded cross-section with a sharper edge. How might contact with the water change as you tilt the board?
Rocker / the curve from nose to tail
A side profile reveals a different geometry from the top view. Sketch two profiles and think about how much of each might meet the water as a rider shifts weight.
Concavity / the shape underneath
Slice an imagined board across its width. Flat, concave, and convex surfaces produce different cross-sections. What would you need to measure to test their effect?
Fins / small shapes, complicated flow
Fin geometry and angle affect forces in moving water. Research uses both controlled measurements and simulations; a single dimension cannot tell us how a whole board will feel.