DivertaX - NOR570
Sailing performance analysis for a Express from 1979, built by Albin and designed by Peter Norlin.
Data provided by the Offshore Racing Congress (ORC)
This cruiser-racer is both agile and competitive, reaching a speed of 6.73 knots on a reach in 10 knots of wind. It is well-suited for mixed conditions with a balanced sail plan, including a symmetric spinnaker for downwind legs. Upwind, it achieves 5.47 knots in moderate winds, making it a versatile choice for both casual cruising and club racing.
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.
Identity
Dimensions
Sail Areas
ORC Rating
Rated boat speeds
| Wind Speed (TWS) | |||||||
|---|---|---|---|---|---|---|---|
| 6 kt | 8 kt | 10 kt | 12 kt | 14 kt | 16 kt | 20 kt | |
| Beat VMG | 2.93 | 3.51 | 3.96 | 4.25 | 4.33 | 4.34 | 4.31 |
| 52° | 4.48 | 5.30 | 5.77 | 6.01 | 6.10 | 6.14 | 6.15 |
| 60° | 4.74 | 5.55 | 5.93 | 6.15 | 6.28 | 6.34 | 6.34 |
| 75° | 4.93 | 5.72 | 6.06 | 6.29 | 6.51 | 6.67 | 6.78 |
| 90° | 5.02 | 5.87 | 6.26 | 6.49 | 6.62 | 6.86 | 7.25 |
| 110° | 5.06 | 5.93 | 6.34 | 6.73 | 7.11 | 7.37 | 7.73 |
| 120° | 4.89 | 5.83 | 6.27 | 6.66 | 7.09 | 7.52 | 8.18 |
| 135° | 4.40 | 5.35 | 6.03 | 6.39 | 6.78 | 7.22 | 8.25 |
| 150° | 3.70 | 4.65 | 5.51 | 6.08 | 6.41 | 6.77 | 7.60 |
| Run VMG | 3.20 | 4.03 | 4.79 | 5.48 | 6.00 | 6.33 | 7.03 |
Boat speed (knots) at wind angle / wind speed