Rigging Dimensions
The four foretriangle measurements sailmakers need to quote a new suit.
I ?
32.75 ft
J ?
10.75 ft
P ?
28.00 ft
E ?
9.75 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 | 136.5 | 12.7 |
| 100% ForetriangleI × J ÷ 2 | 176.0 | 16.4 |
| 150% GenoaTypical light-air headsail | 264.0 | 24.5 |
| Storm Jib~50% of foretriangle, high-cut | 88.0 | 8.2 |
| Symmetric SpinnakerEstimated from I, J | 633.7 | 58.9 |
| Total Working Sail AreaMain + 100% foretriangle | 312.5 | 29.0 |
Foretriangle Diagram
Drawn to scale from published I, J, P, E measurements — Masthead Sloop · Stan Huntingford design
Performance Ratios
How the Us 27 1 Sd carries its sail relative to its displacement.
SA/D Ratio
15.5
Moderate — comfortable coastal cruiser, not overcanvassed.
Mast Height (above DWL)
38.8 ft
Clears the 65 ft ICW fixed-bridge standard with room to spare.
Ballast Ratio
35%
Typical cruising ballast — balanced stability underway.
Typical Sail Inventory
What Us 27 1 Sd owners usually carry and what's worth buying used vs. new.
Mainsail 136.5 ft²
Dacron cross-cut with 2 reef points is standard. Full-batten is a common upgrade.
Replace new
150% Genoa 264.0 ft²
The workhorse headsail. Most boats have one on a furler by now.
Replace new
110% Working Jib ~194 ft²
Good secondary sail for breezy days — used market is strong.
Buy used
Storm Jib 88.0 ft²
Bright orange recommended. Rarely used, hard to justify new.
Buy used
Asymmetric Spinnaker ~634 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 Us 27 1 Sd — Dacron, laminate, and cruising performance tiers.