Rigging Dimensions
The four foretriangle measurements sailmakers need to quote a new suit.
I ?
51.25 ft
J ?
15.75 ft
P ?
44.21 ft
E ?
14.30 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 | 316.1 | 29.4 |
| 100% ForetriangleI × J ÷ 2 | 403.6 | 37.5 |
| 150% GenoaTypical light-air headsail | 605.4 | 56.2 |
| Storm Jib~50% of foretriangle, high-cut | 201.8 | 18.7 |
| Symmetric SpinnakerEstimated from I, J | 1,452.9 | 135.0 |
| Total Working Sail AreaMain + 100% foretriangle | 719.7 | 66.9 |
Foretriangle Diagram
Drawn to scale from published I, J, P, E measurements — Masthead Sloop · George Olson design
Performance Ratios
How the Olson 40 carries its sail relative to its displacement.
SA/D Ratio
24.3
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
53%
Race-oriented ballast ratio — stiff and powerful.
Typical Sail Inventory
What Olson 40 owners usually carry and what's worth buying used vs. new.
Mainsail 316.1 ft²
Dacron cross-cut with 2 reef points is standard. Full-batten is a common upgrade.
Replace new
150% Genoa 605.4 ft²
The workhorse headsail. Most boats have one on a furler by now.
Replace new
110% Working Jib ~444 ft²
Good secondary sail for breezy days — used market is strong.
Buy used
Storm Jib 201.8 ft²
Bright orange recommended. Rarely used, hard to justify new.
Buy used
Asymmetric Spinnaker ~1,453 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 Olson 40 — Dacron, laminate, and cruising performance tiers.