Rigging Dimensions
The four foretriangle measurements sailmakers need to quote a new suit.
I ?
53.75 ft
J ?
19.25 ft
P ?
46.17 ft
E ?
19.00 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 | 438.6 | 40.7 |
| 100% ForetriangleI × J ÷ 2 | 517.3 | 48.1 |
| 150% GenoaTypical light-air headsail | 776.0 | 72.1 |
| Storm Jib~50% of foretriangle, high-cut | 258.7 | 24.0 |
| Symmetric SpinnakerEstimated from I, J | 1,862.4 | 173.0 |
| Total Working Sail AreaMain + 100% foretriangle | 956.0 | 88.8 |
Foretriangle Diagram
Drawn to scale from published I, J, P, E measurements — Cutter · Ted Irwin design
Performance Ratios
How the Irwin 43 Cc Mki carries its sail relative to its displacement.
SA/D Ratio
17.5
Moderate — comfortable coastal cruiser, not overcanvassed.
Mast Height (above DWL)
58.0 ft
Clears the 65 ft ICW fixed-bridge standard at normal tide.
Ballast Ratio
31%
Typical cruising ballast — balanced stability underway.
Typical Sail Inventory
What Irwin 43 Cc Mki owners usually carry and what's worth buying used vs. new.
Mainsail 438.6 ft²
Dacron cross-cut with 2 reef points is standard. Full-batten is a common upgrade.
Replace new
150% Genoa 776.0 ft²
The workhorse headsail. Most boats have one on a furler by now.
Replace new
110% Working Jib ~569 ft²
Good secondary sail for breezy days — used market is strong.
Buy used
Storm Jib 258.7 ft²
Bright orange recommended. Rarely used, hard to justify new.
Buy used
Asymmetric Spinnaker ~1,862 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 Irwin 43 Cc Mki — Dacron, laminate, and cruising performance tiers.