MISTRAL 31
Specifications
Hull
| LOA | 31.1 ft |
| LWL | 23.7 ft |
| Beam | 10.2 ft |
| Draft | 5.2 ft |
| Displacement | 6,000 lb |
| Hull speed1.34·√LWL | 6.5 kn |
About the MISTRAL 31
Derived from the successful 1/2 ton racer 'Roller Coaster'. Later, Trapper Yachts aquired the molds and it became the TRAPPER 950.
Designed by Robert Humphries and built by Fairey Allday Ltd. (UK) in 1978, the Mistral 31 is a fractional sloop with a displacement of 6000.0 lb and a comfort ratio of 16.22. While the exact hulls built count is unknown, owner reports highlight a distinct pattern of structural maintenance needs, particularly regarding deck cores and mast steps.
- Best for:
- This boat suits coastal cruisers and weekend sailors who prioritize a responsive, moderate-displacement hull form over heavy bluewater stability. It is well-suited for owners willing to engage in proactive maintenance of composite structures and mechanical systems.
- Bluewater capability:
- With a capsize ratio of 2.25 and a D/L ratio of 201.21, the Mistral 31 is moderately stable but lacks the heavy displacement typically preferred for serious offshore passage-making. Its bluewater capability is significantly compromised by critical reports of deck core moisture and compression post rot, which pose serious structural risks in heavy weather.
- Comparables:
- Comparable to other late-1970s British fractional sloops like the Hallberg-Rassy 31 or the Hallberg-Rassy 355, the Mistral 31 offers similar performance characteristics but with a lighter displacement and different construction vulnerabilities. It also shares market space with the Tartan 31, though the Mistral's fin keel and fractional rig offer a more modern sailing profile for its era.
Performance
ORC Performance Data(1 certificate)
Measured performance data from ORC (Offshore Racing Congress) certificates.
Polar Diagram
Boat speed (kn) vs. true wind angle. Source: ORC
Racing Ratings
Triple Number
ORC Measured
Sail Areas (ORC)
Speed Table (kn)
| TWA \ TWS | 4 | 6 | 8 | 10 | 12 | 14 | 16 | 20 | 24 |
|---|---|---|---|---|---|---|---|---|---|
| 52° | 3.7 | 4.9 | 5.7 | 6.1 | 6.3 | 6.4 | 6.5 | 6.5 | 6.5 |
| 60° | 3.9 | 5.2 | 5.9 | 6.3 | 6.5 | 6.6 | 6.6 | 6.7 | 6.7 |
| 75° | 4.0 | 5.3 | 6.0 | 6.4 | 6.6 | 6.8 | 6.9 | 7.0 | 7.1 |
| 90° | 3.9 | 5.2 | 6.0 | 6.5 | 6.7 | 6.9 | 7.0 | 7.3 | 7.5 |
| 110° | 3.8 | 5.1 | 6.0 | 6.5 | 6.8 | 7.1 | 7.4 | 7.7 | 8.0 |
| 120° | 3.6 | 4.9 | 5.9 | 6.4 | 6.8 | 7.1 | 7.4 | 8.1 | 8.6 |
| 135° | 3.2 | 4.4 | 5.4 | 6.1 | 6.5 | 6.9 | 7.2 | 8.0 | 9.2 |
| 150° | 2.6 | 3.7 | 4.7 | 5.6 | 6.2 | 6.6 | 6.9 | 7.6 | 8.5 |
| Beat VMG | 2.4 | 3.3 | 3.9 | 4.3 | 4.5 | 4.6 | 4.6 | 4.6 | 4.5 |
| Run VMG | 2.2 | 3.2 | 4.1 | 4.9 | 5.6 | 6.1 | 6.5 | 7.1 | 7.7 |
Pricing
We don't have market pricing data for the MISTRAL 31 yet. If you own one, help other buyers — what did you pay for it? Reports build a community price estimate over time.
Estimated Cost of Ownership
Based on 31.1ft LOA. Actual costs vary by condition, usage, and local rates.
Known Issues & Pre-Purchase Inspection
10 reported issues across 7 systems for the MISTRAL 31, compiled from owner reports in sailing forums and owner-association material.
Unlock the full inspection report
Thinking of buying a MISTRAL 31? This is an in-depth report on the faults this model is known for — so you know exactly what to check when you walk the boat. For the price of a coffee.
- ✓ All 10 specific issues — severity, symptoms & fixes
- ✓ Model-specific pre-purchase inspection checklist
- ✓ Downloadable PDF to take to your surveyor — yours to keep
One-time $2.99 · secure checkout by Stripe · instant access · 30 days online, PDF yours to keep
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Used sails that fit the MISTRAL 31
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