Rigging Dimensions
The four foretriangle measurements sailmakers need to quote a new suit.
I ?
1.17 ft
J ?
7.80 ft
P ?
190.00 ft
E ?
204.39 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 | 19,417.1 | 1,803.9 |
| 100% ForetriangleI × J ÷ 2 | 4.6 | 0.4 |
| 150% GenoaTypical light-air headsail | 6.8 | 0.6 |
| Storm Jib~50% of foretriangle, high-cut | 2.3 | 0.2 |
| Symmetric SpinnakerEstimated from I, J | 16.4 | 1.5 |
| Total Working Sail AreaMain + 100% foretriangle | 19,421.6 | 1,804.3 |
Foretriangle Diagram
Drawn to scale from published I, J, P, E measurements — Masthead Sloop · C.raymond Hunt Associates design
Performance Ratios
How the Oday 20 carries its sail relative to its displacement.
SA/D Ratio
—
Sail Area / Displacement ratio not published.
Mast Height (above DWL)
— ft
Air draft not published — measure yours before any bridge transit.
Ballast Ratio
17%
Light ballast — tends to be tender; reef earlier.
Typical Sail Inventory
What Oday 20 owners usually carry and what's worth buying used vs. new.
Mainsail 19,417.1 ft²
Dacron cross-cut with 2 reef points is standard. Full-batten is a common upgrade.
Replace new
150% Genoa 6.8 ft²
The workhorse headsail. Most boats have one on a furler by now.
Replace new
110% Working Jib ~5 ft²
Good secondary sail for breezy days — used market is strong.
Buy used
Storm Jib 2.3 ft²
Bright orange recommended. Rarely used, hard to justify new.
Buy used
Asymmetric Spinnaker ~16 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 Oday 20 — Dacron, laminate, and cruising performance tiers.