Uma - NOR3557
Sailing performance analysis for a X-102 Mk I from 1981, built by X-Yachts and designed by Niels Jeppesen.
Data provided by the Offshore Racing Congress (ORC)
The X-102 Mk I is a performance sailboat that truly stands out with its quick and responsive nature. It achieves 6.16 knots upwind in 10 knots of wind and reaches speeds of 7.35 knots on a reach in the same conditions. Equipped with a symmetric spinnaker, the boat performs well downwind, although the spinnaker is modest for its size. The balanced sail plan features a jib that complements the mainsail effectively, making it well-powered for its size.
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 | 3.43 | 4.10 | 4.59 | 4.78 | 4.86 | 4.89 | 4.90 |
| 52° | 5.18 | 6.12 | 6.59 | 6.77 | 6.84 | 6.88 | 6.92 |
| 60° | 5.47 | 6.35 | 6.75 | 6.95 | 7.04 | 7.09 | 7.13 |
| 75° | 5.70 | 6.51 | 6.88 | 7.14 | 7.33 | 7.44 | 7.54 |
| 90° | 5.63 | 6.50 | 6.92 | 7.21 | 7.47 | 7.70 | 7.98 |
| 110° | 5.37 | 6.44 | 6.96 | 7.35 | 7.72 | 8.04 | 8.39 |
| 120° | 5.17 | 6.27 | 6.86 | 7.26 | 7.65 | 8.03 | 8.73 |
| 135° | 4.65 | 5.69 | 6.51 | 6.97 | 7.35 | 7.73 | 8.52 |
| 150° | 3.94 | 4.94 | 5.84 | 6.56 | 6.97 | 7.33 | 8.06 |
| Run VMG | 3.41 | 4.28 | 5.07 | 5.80 | 6.45 | 6.88 | 7.58 |
Boat speed (knots) at wind angle / wind speed