Rigging Dimensions
The four foretriangle measurements sailmakers need to quote a new suit.
I ?
48.00 ft
J ?
18.00 ft
P ?
40.08 ft
E ?
15.25 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 | 305.6 | 28.4 |
| 100% ForetriangleI × J ÷ 2 | 432.0 | 40.1 |
| 150% GenoaTypical light-air headsail | 648.0 | 60.2 |
| Storm Jib~50% of foretriangle, high-cut | 216.0 | 20.1 |
| Symmetric SpinnakerEstimated from I, J | 1,555.2 | 144.5 |
| Total Working Sail AreaMain + 100% foretriangle | 737.6 | 68.5 |
Foretriangle Diagram
Drawn to scale from published I, J, P, E measurements — Masthead Ketch · C. William Lapworth design
Performance Ratios
How the Cal 46 Iii 1975 carries its sail relative to its displacement.
SA/D Ratio
14.2
Moderate — comfortable coastal cruiser, not overcanvassed.
Mast Height (above DWL)
— ft
Air draft not published — measure yours before any bridge transit.
Ballast Ratio
27%
Light ballast — tends to be tender; reef earlier.
Typical Sail Inventory
What Cal 46 Iii 1975 owners usually carry and what's worth buying used vs. new.
Mainsail 305.6 ft²
Dacron cross-cut with 2 reef points is standard. Full-batten is a common upgrade.
Replace new
150% Genoa 648.0 ft²
The workhorse headsail. Most boats have one on a furler by now.
Replace new
110% Working Jib ~475 ft²
Good secondary sail for breezy days — used market is strong.
Buy used
Storm Jib 216.0 ft²
Bright orange recommended. Rarely used, hard to justify new.
Buy used
Asymmetric Spinnaker ~1,555 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 Cal 46 Iii 1975 — Dacron, laminate, and cruising performance tiers.