SAILING TEST

Trim, load & motion.

A floating half-cylinder hull, supported by sphere buoyancy on animated water.

Click the water view, then hold:
← / → or A / D · adjust rudder angle
Space · centre rudder
↑ / ↓ or W / S · motor forward / reverse
Release to keep the rudder angle and stop thrust.

Rudder0° centred

Rudder water force0.0 N

Motor thrust0 N

Rudder ±40° · 35°/s
Rudder needs water flow · motor works forward and reverse
Rudder force is separate from the hull CLR.

Outhaul95% tight

EasedTight

Clew 1 cm in · peak 1 cm in

Fixed sail mounts slide along boom and gaff.
No outhaul rope or spring.

Mainsheet length1.90 m

Hauled inEased out

Adjusts live · boom moves freely when slack
Centreline lead · same length on either tack

Span — · tension —

Jib sheet3.35 m

Leeward sheet trims automatically; windward sheet stays slack.

One working length on either tack. Automatic trim uses apparent wind 12–165° off the bow; both sheets ease outside that range.

Mast wind drag: — N · active with sails lowered

Air model

View lift & drag curve ↗
Original fit with early lift shifted to 5° and 10°
0–10°: drag extends gently from 0.14 to 0.15
Boat speed & VMG polars ↗

Wind speed8.0 m/s · 15.6 kn

0–25 m/s · up to 48.6 knots
Loading fades as the sail heels flat.

Flow heading202.5°

Air travels toward: 0° North · 90° East
Fixed world bearing · N = +Z, E = +X

Lift Drag arrows ×5

Arrow scale0.4 m/N

Display only · arrow length capped at 1.5 m

Net sail load Lateral water resistance

Centres · hull-local X, Y, Z
CE · sail effort
—
CLR · hull lateral resistance
—
Local −X is forward; Y is above the deck.
Pink dot = wet hull centre · turning moment is separate.

Hold boat in place

Ocean waves

Wave amplitude0.30 m

Noise scale12.00 m

Animation speed0.60 m/s

Small wave detail0.35

Perlin waves · height 0 gives flat water
Settings update live · pause freezes the waves
Buoyancy samples the surface at each sphere.

Hull + onboard load150 kg

Total hull, equipment, stores and people · spread across all hull spheres. Excludes rig and keel ballast.

Ballast + upper load300 kg

Distributed between keel, bilge and upper spheres · changing either weight restarts the boat in all open scenes.

Show buoyancy spheres & force

Volume-matched sphere samples

Hull buoyant force—

Masthead float lift—

Hidden masthead flotation · 0 kg
65 L effective volume · lifts when immersed

Lateral water force—

Displaced volume—

Displaced water—

Hull + ballast + rig—

Deepest draft—

Heel / pitch—

Combined centre of mass · world X, Y, Z
—

Centre of buoyancy · world X, Y, Z
—

Buoyancy moment · X, Y, Z about hull centre of mass
—

Purple arrow = buoyancy · 1 m per 1,500 N (3 m cap)
Gold spheres carry ballast · wet spheres brighten
Fresh water, 1,000 kg/m³ · all motion free.
In calm equilibrium, displaced water mass matches boat mass.

Rig dimensions & masses

9.06 m²2.27 kg

Sail grid

Low-stretch sail & ropes · free to bend

Show sail grid Show vertex bodies

Free heel, pitch & heading.
Buoyancy plus approximate water resistance.
Existing polar plots describe the earlier ground sled.

RIGGING STUDYApparent wind · corners unloaded

↗ Lift↗ Drag ×5↗ Net load

Assembling the rig…

MAST 6 m

BOOM free pivot

WIND & BOAT VELOCITY

CE sail effort

CLR lateral resistance

True windToward 135°North fixed · bow 270°

NET LOAD & MOTION

Forward speed0.00 m/s

Sideways speed0.000 m/s

Apparent wind—

Forward sail force0.0 N

Sideways sail force0.0 N

Net sail load0.0 N

Green = sail force · pink = lateral water force
Blue = true wind · white = boat motion · orange = apparent wind
Purple = buoyancy · velocity arrows share a scale
Sail & lateral force: 0.03 m/N · capped at 3 m

VERTEX 3, 4

Lift0.000 N

Drag0.000 N

Last applied loads · values in newtons

Click the sail to select a vertex.

Animated water · grid 1 metre

Starting——