Rigging Dimensions
The four foretriangle measurements sailmakers need to quote a new suit.
I ?
31.95 ft
J ?
10.50 ft
P ?
36.00 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 | 274.5 | 25.5 |
| 100% ForetriangleI × J ÷ 2 | 167.7 | 15.6 |
| 150% GenoaTypical light-air headsail | 251.6 | 23.4 |
| Storm Jib~50% of foretriangle, high-cut | 83.9 | 7.8 |
| Symmetric SpinnakerEstimated from I, J | 603.9 | 56.1 |
| Total Working Sail AreaMain + 100% foretriangle | 442.2 | 41.1 |
Foretriangle Diagram
Drawn to scale from published I, J, P, E measurements — Fractional Sloop · Robert G. Henry Jr. design
Performance Ratios
How the Oxford 400 carries its sail relative to its displacement.
SA/D Ratio
17.2
Moderate — comfortable coastal cruiser, not overcanvassed.
Mast Height (above DWL)
— ft
Air draft not published — measure yours before any bridge transit.
Ballast Ratio
45%
Race-oriented ballast ratio — stiff and powerful.
Typical Sail Inventory
What Oxford 400 owners usually carry and what's worth buying used vs. new.
Mainsail 274.5 ft²
Dacron cross-cut with 2 reef points is standard. Full-batten is a common upgrade.
Replace new
150% Genoa 251.6 ft²
The workhorse headsail. Most boats have one on a furler by now.
Replace new
110% Working Jib ~185 ft²
Good secondary sail for breezy days — used market is strong.
Buy used
Storm Jib 83.9 ft²
Bright orange recommended. Rarely used, hard to justify new.
Buy used
Asymmetric Spinnaker ~604 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 Oxford 400 — Dacron, laminate, and cruising performance tiers.