The Bunyip 20 is with a quick, snappy motion best suited to day sailing.
Hull Speed
The theoretical displacement-mode speed limit — determined by waterline length, not engine or sail power.
5.8 kts
A displacement hull pushes a bow wave whose speed is limited by the waterline length.
With a waterline of 18.6′, the Bunyip 20 tops out around 5.8 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √18.6′ LWL = 5.8 kts
Performance Ratios
Racing handicap, sail-carrying power, stability and comfort — and what each one actually tells you about a day on the water.
Displacement / Length
49
Ultralight — responsive and fast, but carries less stores.
Comfort Ratio
2.3
Quick, snappy motion — better for day sails and racing than long passages.
Capsize Screening
4.96
Above the 2.0 offshore threshold — best suited for coastal and protected waters.
Hull Speed
5.8kts
Pounds/Inch Immersion
4lbs
Weight needed to sink the hull one inch — loading sensitivity.
Motion & Offshore Suitability
Two ratios that matter most when you're planning passages — how the boat feels in a seaway, and whether the hull geometry is suitable for open ocean.
Comfort Ratio
2.3
Quick, snappy motion — better for day sails and racing than long passages.
Under 20 — Snappy, racing motion
20–30 — Acceptable coastal
30–40 — Good offshore comfort
Over 40 — Very comfortable offshore
Capsize Screening Formula
4.96
Above the 2.0 offshore threshold — best suited for coastal and protected waters.
Under 2.0 — Acceptable for offshore
Over 2.0 — Coastal / protected waters
How It Compares
Side-by-side with the boats most often cross-shopped against the Bunyip 20.
| Bunyip 20 | Astus 201 | Hobie Fox | Nacra 20 | Shark Catamaran | Tornado Catamaran | |
|---|---|---|---|---|---|---|
| Dimensions | ||||||
| LOA | 20.0 | 20.0 | 20.0 | 20.0 | 20.0 | 20.0 |
| LWL | 18.6 | 19.2 | — | — | 17.0 | — |
| Beam | 11.0 | 12.7 | 8.5 | 8.5 | 10.0 | 10.0 |
| Displacement | 700 | 838 | 419 | 390 | 300 | 300 |
| Sail Area | — | — | — | — | 235 | 235 |
| Performance | ||||||
| SA/Disp | — | — | — | — | 84.0 | — |
| Comfort | 2.3 | 2.2 | 2.1 | 1.9 | — | 1.2 |
| Capsize | 4.96 | 5.41 | 4.55 | 4.66 | — | 5.98 |
| Hull Speed | 5.8 | 5.9 | 5.5 | 5.5 | — | 5.5 |