Butterfly - NOR8100
Sailing performance analysis for a MAMBA 29 (series year 1981), built by and designed by Jan Becker.
Data provided by the Offshore Racing Congress (ORC) · Certificate issued 24/10/2025
As a comfort cruiser, this boat offers a smooth sailing experience, making it ideal for relaxed journeys. It reaches a modest 5.4 knots upwind in 10 knots of wind, and while not the fastest downwind, it maintains 4.8 knots with its symmetric spinnaker in moderate conditions. The large genoa complements the mainsail, providing ample power on a reach.
Sailing performance as a polar diagram
A polar diagram shows boat speed at different wind angles and wind speeds. The distance from center represents boat speed in knots, and the angle represents the boats angle to the wind. The wind speed is shown as true wind speed (TWS), not apparent wind speed. Likewise, the wind angle is shown as true wind angle (TWA), not apparent wind angle.
Beat: Sailing upwind (toward the wind)
Beam Reach: Sailing across the wind
Run: Sailing downwind (away from the wind)
VMG Performance
Wind Speed (columns): True wind speed (TWS) in knots - the actual wind speed, not the apparent wind you feel on deck.
VMG (Velocity Made Good) is your effective speed toward your destination, not your actual boat speed.
Beat VMG (top bars): Speed made good when sailing upwind. Higher is better - it means you're reaching the windward mark faster.
Run VMG (bottom bars): Speed made good when sailing downwind. Higher is better - it means you're reaching the leeward mark faster.
Measured sails
Spinnaker measurements were not supported before this season's certificates. If no spinnaker is shown, that's why.
Measurements
🏁 Race Results
| Date | Event | Result | Class | Skipper |
|---|---|---|---|---|
| 2026 | ||||
| 10.01.2026 | Nyttårsseilasen 2026 | 6/7 | NOR Rating | Arie Jan STIERMAN |
| 2025 | ||||
| 23.11.2025 | SF1928 Vinterserie | 6/8 | Norrating | Arie Jan Stierman |
| 2024 | ||||
| 01.05.2024 | Onsdagsseilaser våren 2024 | 7/7 | Liten Klasse | Arie Jan STIERMAN |
Race results from manage2sail.com & sailracesystem.no
Identity
Dimensions
Sail Areas
ORC Rating
Rated boat speeds
| Wind Speed (TWS) | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| 4 kt | 6 kt | 8 kt | 10 kt | 12 kt | 14 kt | 16 kt | 20 kt | 24 kt | |
| Beat VMG | 2.27 | 3.12 | 3.76 | 4.15 | 4.34 | 4.42 | 4.47 | 4.51 | 4.45 |
| 52° | 3.54 | 4.73 | 5.53 | 5.98 | 6.19 | 6.27 | 6.32 | 6.37 | 6.37 |
| 60° | 3.77 | 4.97 | 5.74 | 6.14 | 6.35 | 6.44 | 6.49 | 6.55 | 6.57 |
| 75° | 3.86 | 5.10 | 5.87 | 6.28 | 6.51 | 6.66 | 6.74 | 6.84 | 6.90 |
| 90° | 3.71 | 4.98 | 5.84 | 6.31 | 6.54 | 6.75 | 6.92 | 7.11 | 7.23 |
| 110° | 3.65 | 4.97 | 5.92 | 6.43 | 6.75 | 7.00 | 7.18 | 7.43 | 7.51 |
| 120° | 3.47 | 4.78 | 5.76 | 6.35 | 6.71 | 7.01 | 7.30 | 7.78 | 8.11 |
| 135° | 3.07 | 4.28 | 5.29 | 6.04 | 6.49 | 6.83 | 7.16 | 7.84 | 8.71 |
| 150° | 2.53 | 3.66 | 4.68 | 5.52 | 6.15 | 6.54 | 6.85 | 7.48 | 8.26 |
| Run VMG | 2.19 | 3.17 | 4.06 | 4.82 | 5.48 | 6.01 | 6.40 | 6.99 | 7.58 |
Boat speed (knots) at wind angle / wind speed