The Grand Mistral 80 is with acceptable motion comfort for coastal passages.
Hull Speed
The theoretical displacement-mode speed limit — determined by waterline length, not engine or sail power.
11.3 kts
A displacement hull pushes a bow wave whose speed is limited by the waterline length.
With a waterline of 70.8′, the Grand Mistral 80 tops out around 11.3 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √70.8′ LWL = 11.3 kts
Performance Ratios
Racing handicap, sail-carrying power, stability and comfort — and what each one actually tells you about a day on the water.
Ballast / Displacement
49.4%
Race-oriented ballast ratio — very stiff and powerful.
Displacement / Length
68
Ultralight — responsive and fast, but carries less stores.
Comfort Ratio
20.5
Acceptable coastal comfort — fine for weekends, notice the chop offshore.
Capsize Screening
2.16
Above the 2.0 offshore threshold — best suited for coastal and protected waters.
Hull Speed
11.3kts
Pounds/Inch Immersion
31lbs
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
20.5
Acceptable coastal comfort — fine for weekends, notice the chop offshore.
Under 20 — Snappy, racing motion
20–30 — Acceptable coastal
30–40 — Good offshore comfort
Over 40 — Very comfortable offshore
Capsize Screening Formula
2.16
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 Grand Mistral 80.
| Grand Mistral 80 | Baltic 73 | Mystic 76 | Oyster 745 | Swan 77 | Swan 80 2 S | |
|---|---|---|---|---|---|---|
| Dimensions | ||||||
| LOA | 80.4 | 73.2 | 76.0 | 74.6 | 78.8 | 82.3 |
| LWL | 70.8 | 60.7 | 61.7 | 65.7 | 60.3 | 72.8 |
| Beam | 20.3 | 18.0 | 20.9 | 19.4 | 19.7 | 20.0 |
| Displacement | 54 | 77 | 105 | 118 | 112 | 79 |
| Ballast | 26 | 29 | 38 | — | 39 | 39 |
| Sail Area | — | 2 | 2 | 3 | — | 3 |
| Performance | ||||||
| SA/Disp | — | 22.0 | 17.5 | 19.9 | — | 28.9 |
| Bal/Disp | 49.4 | 38.6 | — | — | 35.3 | — |
| Comfort | 20.5 | 39.3 | 43.0 | 51.9 | — | 30.1 |
| Capsize | 2.16 | 1.70 | 1.78 | 1.58 | — | 1.86 |
| Hull Speed | 11.3 | 10.4 | 10.5 | 10.9 | — | 11.4 |