Rigging Dimensions
The four foretriangle measurements sailmakers need to quote a new suit.
I ?
50.88 ft
J ?
14.43 ft
P ?
43.80 ft
E ?
16.07 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 | 351.9 | 32.7 |
| 100% ForetriangleI × J ÷ 2 | 367.1 | 34.1 |
| 150% GenoaTypical light-air headsail | 550.6 | 51.2 |
| Storm Jib~50% of foretriangle, high-cut | 183.5 | 17.1 |
| Symmetric SpinnakerEstimated from I, J | 1,321.6 | 122.8 |
| Total Working Sail AreaMain + 100% foretriangle | 719.0 | 66.8 |
Foretriangle Diagram
Drawn to scale from published I, J, P, E measurements — Masthead Sloop · Niels Jeppesen design
Performance Ratios
How the Imx 38 carries its sail relative to its displacement.
SA/D Ratio
28.2
Performance-oriented — carries a lot of sail for its weight.
Mast Height (above DWL)
— ft
Air draft not published — measure yours before any bridge transit.
Ballast Ratio
52%
Race-oriented ballast ratio — stiff and powerful.
Typical Sail Inventory
What Imx 38 owners usually carry and what's worth buying used vs. new.
Mainsail 351.9 ft²
Dacron cross-cut with 2 reef points is standard. Full-batten is a common upgrade.
Replace new
150% Genoa 550.6 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 183.5 ft²
Bright orange recommended. Rarely used, hard to justify new.
Buy used
Asymmetric Spinnaker ~1,322 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 Imx 38 — Dacron, laminate, and cruising performance tiers.