Editing a board

Outline

The plan shape, seen from above. Mirrored about the stringer, so you edit one half and both update.

Rocker

The profile from the side: two curves, deck and bottom. The gap between them is the thickness flow.

Cross-section

One station across the board, rail to rail. Use [ and ] to page through stations.

3D

The tessellated surface. Useful for spotting a bump you cannot see in a single profile.

The quad view shows all four at once. Number keys switch views — see shortcuts. Phones do not get the quad view: four panes in that width leaves none of them usable, so a phone opens on the outline and switches between the single views instead.

Split view is the middle ground: two full-width panes, one above the other, each with a picker where its title would be — so you can put the outline over the rocker, or the outline over a cross-section, and read both at full window width. Picking the pane the other half is already showing swaps the two rather than doubling it up. The pairing is remembered between sessions. Split is a desktop layout only: halving the height of a tablet or phone window leaves two panes too short to work in, so the tab and its number key are not offered below 1024px wide.

With a mouse there is a shortcut that skips the tabs: double-click a pane title in the quad view to blow that pane up to the full viewport, and double-click the title again to drop back to quad. The controls in the title bar are unaffected — only the title itself switches views.

On a touch screen, outline and rocker are drawn nose-up whenever the pane is taller than it is wide — which on a phone held upright it is. A board is about four times longer than it is wide, so lying it across a narrow pane wastes most of the height; standing it up trades that for about half as much again in size. Turn the phone sideways and the board lies down again, because a wide pane already fits it the better way round. Nothing to set, and it never applies to the cross-section view, which is already the shape of its pane.

Right-click clear space in any 2D view and choose Set reference curveto capture its current curves. A faint copy stays underneath as you edit, revealing the original shape wherever the live curves move away. Choose the option again to replace the reference, or choose Clear reference curve to remove it. References are temporary: one lasts while its view stays open, is cleared when you move to another cross-section, and is never saved with the board.

Turn on Tunni controls from the View menu, or right-click a 2D view and check Show Tunni controls, to adjust both handles of a curve segment together. Drag the amber dashed line to scale the handles together, or drag its diamond to adjust their balance and strength. The curve endpoints and tangent directions stay fixed. Double-click the diamond to balance the handles. Controls are hidden for degenerate geometry, and a drag holds its last valid shape while a handle would cross its endpoint. The setting applies to every 2D view and stays on as you switch views and cross-sections; each drag is one undo step. Controls appear only on the editable half of mirrored views.

The 3D view can draw reference lines directly on the surface. Two buttons in the 3D controls toggle them independently.

Stringer

An amber line tracing the centreline: down the deck from nose to tail, and back along the bottom. Together they outline the stringer plane, so you read the rocker and the deck crown at the same time.

Sections

A red ring around the board at every cross-section, with the station you are currently editing drawn in cyan. Useful for judging whether your stations are spaced sensibly, and for seeing which one a change belongs to.

The lines are computed from the same surface the mesh is built from, so they sit on the board rather than floating near it. Both toggles are remembered between sessions, along with the rest of the 3D appearance settings.

Drag a point to move it. Selecting one reveals its tangent handles: drag those to change how the curve leaves the point. Longer handles make a fuller curve; shorter ones tighten it.

Hovering a point or tangent enlarges it; selecting it turns it orange. Its exact X/Y position then appears in that pane's header, where you can type a value or use the number field arrows for unit-aware increments (5 mm, 0.5 cm, or 0.25 in). Corner points stay green and square so they remain distinct from smooth points.

Press Esc to clear a selected point or tangent handle. On a touch screen, tapping empty canvas does the same — it also releases a focused station.

Right-click a control point to fair its local curve, switch between smooth and corner, select either tangent, or delete it. On the outline and rocker the two tangents are named for the end of the board they point at — tail and nose — so the labels still read true when a phone draws the board nose-up. A cross-section has neither end nearer the nose, so its handles stay left and right. Right-click a tangent to collapse it to zero length; a selected collapsed tangent can be right-clicked again and extended so it is easy to grab. On a touch screen, press and hold in place for the same menu — holding still is what distinguishes it from a drag, so it will not interrupt one you have started.

Press Delete to remove the selected point. The curve re-fits through the remaining points.

Lock a point to keep the direction of its tangent handles while you work on their length. Select the point or one of its handles and click the padlock in the pane's header, press L, or right-click the point or a handle and choose Lock handle angles. A locked point shows a short bar across each locked handle's line.

A locked handle slides along its line: drag it anywhere and it only gets longer or shorter, so tuning how full a curve is can no longer tip its angle by accident. Drag it back through the point and it collapses to zero length rather than flipping round; drag it out again and it comes back the same way. On a smooth point the other handle keeps its own length and direction. With a locked handle selected, the pane header shows its length instead of X and Y: type a value, or use the arrow keys to step it. The sidebar Control point section shows its X and Y read-only, with the length below them.

The lock holds through the other point tools too. Fair curve sets new lengths along the locked directions, Extend handle grows a collapsed handle along its lock, and moving the point carries its handles with it. To lock handles level or upright, use the horizontal or vertical align buttons in the sidebar Control point section: aligning a locked point turns its lock with it. Resizing the board scales the locks with the shape.

Locks are part of the board. Locking and unlocking undo like any other edit, and locks are saved in Wooden Surfboard Designer's own .board.json files and share links. A .brd export leaves them out — BoardCAD has no such setting — so the curve is unchanged but its points come back unlocked.

You define cross-sections at particular stations; the surface between them is interpolated, so you do not need many. Add one where the shape needs to change character — through the hips, or where a concave starts — rather than at regular intervals.

Sections can be copied and pasted, which is the quickest way to hold a rail shape constant through a stretch of the board and then vary it deliberately.

Every station shows as a dashed vertical line in the outline and rocker views, with a diamond handle at each end. Click a handle to select the station — it turns orange — then drag it along the board to reposition it. The position appears beside the handle as you drag, in your chosen units, and a station can never pass its neighbours, so the order never changes under you. The whole drag is a single undo step. Press Esc to release the handle.

Right-clicking a handle offers to add a station either side of it, or to delete it. For an exact position, type into the field beside the station counter in the cross-section pane header, or use its steppers — they nudge by a sensible amount for the current unit.

Moving a station carries its profile with it, so the surface between the neighbouring stations changes shape. That is deliberate: you are sliding a control station, not re-sampling the existing surface.

Right-click in the cross-section view and pick a shape under Rail preset to restyle the station you are on. It applies to that one section — build a rail that changes along the board by stepping through stations and choosing as you go, which is what a shaper does anyway: soft through the nose, tucked through the middle, hard off the tail.

Only the rail band is re-cut. Like marking bands in from the rail and planing just those, a preset works between two blend points — one in from the rail on the deck, a narrower one on the bottom — and joins smoothly to what is already there. Your deck crown, your vee, your concave: all untouched. The station’s width and thickness do not move either, so the outline and rocker stay put.

It lands as one undo step, and what you get back is an ordinary profile — drag the points afterwards, or leave it.

The ratio in a name is where the rail’s apex — its widest point — sits between those two marks. A 50/50 puts it halfway up the rail; an 80/20 puts it near the bottom, where it makes an edge for water to leave from.

It is the midpoint of the rail, not of the deck and bottom planes. On a board with a flat bottom and a domed deck the rail blends into that dome up top and into the flat underneath, so even a 50/50 apex measures below mid-thickness — a third of the way up is normal on a shortboard. Dome the bottom too, as a longboard or a hull does, and the apex climbs back toward the middle on its own.

50/50 soft

Apex at mid-rail, round and symmetric. Forgiving and easy to lean on — longboards, noseriders, and the nose of most boards.

60/40 tucked

Apex 40% up with a tucked-under edge. The all-round rail through the middle of a board: holds in a turn, releases once there is speed.

70/30 tucked

A step lower and harder than 60/40. Sits between the middle of the board and the fin area.

80/20 hard

Apex low, with the bottom running flat to a crisp edge that sheds water cleanly. The last stretch of a performance tail.

Boxy

Full, high-volume rail that holds its width and rolls over from well inboard. Stable and buoyant — beginner boards and small-wave shapes.

Pinched

Low-volume rail that turns in late and thin. Sensitive and quick to bite; wants an experienced back foot, and a domed deck under it.

Egg

Drawn-out elliptical 50/50 with a soft apex and a long roll. Smooth and predictable — retro and hybrid shapes.

Knifey

Very thin, almost flat ellipse with minimal buoyancy. Use at the tips only — it catches if carried through the middle.

The outline can fold back into the tail to make a swallow or a wing. Volume, planshape area, the 3D mesh and every export understand the cutout, so the numbers stay honest.

One shape is not supported: a single notch only, so batwing tails with two cutouts cannot be described.

Every edit lands on a labelled undo stack — ⌘Z and ⇧⌘Z. A drag is one step, not one step per pixel, so undo moves in the units you actually think in.

Your working board is saved to this device continuously, so closing the tab and coming back restores it, along with the view you were in and the camera position. The one exception is the quad view on a phone, which is not offered there — a board last left in it opens on the outline, and the stored preference is kept for the next time you open the editor on a bigger screen.