Rigging Dimensions
The four foretriangle measurements sailmakers need to quote a new suit.
I ?
50.00 ft
J ?
14.70 ft
P ?
43.25 ft
E ?
16.00 ft
Sail Area Breakdown
Calculated from rigging dimensions. Use these as your starting point when ordering a new suit.
| Sail | Area (ft²) | Area (m²) |
|---|---|---|
| MainsailP × E ÷ 2 | 346.0 | 32.1 |
| 100% ForetriangleI × J ÷ 2 | 367.5 | 34.1 |
| 150% GenoaTypical light-air headsail | 551.3 | 51.2 |
| Storm Jib~50% of foretriangle, high-cut | 183.8 | 17.1 |
| Symmetric SpinnakerEstimated from I, J | 1,323.0 | 122.9 |
| Total Working Sail AreaMain + 100% foretriangle | 713.5 | 66.3 |
Foretriangle Diagram
Drawn to scale from published I, J, P, E measurements — Masthead Sloop · Stephen Jones design
Performance Ratios
How the Starlight 39 carries its sail relative to its displacement.
SA/D Ratio
15.7
Moderate — comfortable coastal cruiser, not overcanvassed.
Mast Height (above DWL)
56.8 ft
Clears the 65 ft ICW fixed-bridge standard at normal tide.
Ballast Ratio
36%
Typical cruising ballast — balanced stability underway.
Typical Sail Inventory
What Starlight 39 owners usually carry and what's worth buying used vs. new.
Mainsail 346.0 ft²
Dacron cross-cut with 2 reef points is standard. Full-batten is a common upgrade.
Replace new
150% Genoa 551.3 ft²
The workhorse headsail. Most boats have one on a furler by now.
Replace new
110% Working Jib ~404 ft²
Good secondary sail for breezy days — used market is strong.
Buy used
Storm Jib 183.8 ft²
Bright orange recommended. Rarely used, hard to justify new.
Buy used
Asymmetric Spinnaker ~1,323 ft²
Popular downwind upgrade — easier than symmetric for shorthanded sailing.
Optional
Replacement Cost Estimator
Get a rough price range for a new mainsail and genoa for the Starlight 39 — Dacron, laminate, and cruising performance tiers.