J 125
Boat highlights
J 125 is currently estimated in the Good band with an SBP score of 114.
Length overall
41.0 ft
Primary sail area
786 ft²
Displacement
8,351 lbs
Quick actions
Jump back to browsing, customize this design, or share it with your crew.
Performance Analysis
Detailed performance metrics and polar diagram for J 125.
Methodology note: SBP scores, polar diagrams, hull-speed values, and derived ratios are estimates. Use them for comparison and planning support—not as a substitute for manufacturer specifications, measured sea trials, rating certificates, professional weather routing, or safety margins. Review how we rate boats.
Performance Metrics
Speed Estimates
| Wind Speed (kn) | Beat VMG (kn) | Run VMG (kn) |
|---|---|---|
| 6 | 4.0 | 4.2 |
| 8 | 4.8 | 5.4 |
| 10 | 5.4 | 6.5 |
| 12 | 5.7 | 7.1 |
| 14 | 5.8 | 7.7 |
| 16 | 5.8 | 8.7 |
| 20 | 5.9 | 10.9 |
Polar Diagram
Wind Speed (kn)
Key Specifications
Explore the hull dimensions and sail plan for J 125.
Dimensions
Sails
Construction ratios
Discussion
Share your experiences with J 125.
You need to be logged in to join the discussion.
Log in to commentData sources and methodology
Published specifications are kept separate from calculated ratios and estimated performance. SBP and speed outputs are model-based estimates, not owner ratings or certified handicaps.
- Specifications
- verified
- Ratios
- derived
- Performance
- estimated
Last checked: 27 Aug 2026. Source: J Boats official website. Read the SBP methodology.
