VIPER 640
Specifications
Hull
| LOA | 21.08 ft |
| LWL | 19.08 ft |
| Beam | 8.17 ft |
| Draft | 4.83 ft/ 1.83 ft min |
| Displacement | 700 lb |
| Ballast | 185 lb |
| Hull speed1.34·√LWL | 5.9 kn |
Rig & Sails
| Iforetriangle height | 21.98 ft |
| Jforetriangle base | 7.48 ft |
| Pmainsail luff | 25.62 ft |
| Emainsail foot | 10.07 ft |
| FLforestay | 7.5 ft |
| Mainsail | 221.5 sq ft |
| Jib (100%) | 82.2 sq ft |
| Spinnaker | 139.7 sq ft |
About the VIPER 640
Rondar Raceboats was appointed the class builder in 2005. Asym. spin. area 425 sf. Keel is fastened with 2 bolts while sailing. Can be raised for trailering and launched in 2 feet of water. . 2 piece carbon spar.
Performance
ORC Performance Data(4 certificates)
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° | 4.2 | 5.4 | 6.0 | 6.3 | 6.5 | 6.6 | 6.7 | 6.8 | 6.7 |
| 60° | 4.4 | 5.6 | 6.3 | 6.7 | 6.9 | 7.1 | 7.2 | 7.4 | 7.3 |
| 75° | 4.4 | 5.8 | 6.6 | 7.2 | 7.6 | 8.0 | 8.3 | 8.7 | 8.8 |
| 90° | 4.4 | 5.7 | 6.6 | 7.6 | 8.3 | 8.8 | 9.3 | 9.9 | 10.3 |
| 110° | 4.4 | 5.9 | 6.9 | 7.7 | 8.4 | 9.4 | 10.2 | 11.4 | 12.3 |
| 120° | 4.3 | 5.8 | 7.0 | 8.1 | 8.9 | 9.7 | 10.4 | 12.0 | 13.1 |
| 135° | 4.0 | 5.3 | 6.4 | 7.8 | 9.3 | 10.5 | 11.4 | 13.2 | 14.7 |
| 150° | 3.2 | 4.5 | 5.6 | 6.5 | 7.9 | 9.3 | 10.9 | 13.9 | 16.3 |
| Beat VMG | 2.7 | 3.6 | 4.2 | 4.4 | 4.4 | 4.5 | 4.5 | 4.5 | 4.4 |
| Run VMG | 2.8 | 3.9 | 4.8 | 5.7 | 6.8 | 8.1 | 9.4 | 12.1 | 14.5 |
Images
Estimated Value
Low ConfidenceAsking price by model year
7 listings · boat years 1996–2013 · median $15,500
Each dot is one listing · hover for details · dashed red line marks the median · obvious data-entry outliers (top & bottom 2.5%) excluded.
Estimated Cost of Ownership
Based on 21.08ft LOA. Actual costs vary by condition, usage, and local rates.
Featured YouTube Videos
Articles & Reviews
Known Issues & Pre-Purchase Inspection
7 reported issues across 5 systems for the VIPER 640, compiled from owner reports in sailing forums and owner-association material.
Unlock the full inspection report
Thinking of buying a VIPER 640? 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 7 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 VIPER 640
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