Rigging Dimensions
The four foretriangle measurements sailmakers need to quote a new suit.
I ?
0.70 ft
J ?
8.21 ft
P ?
— ft
E ?
— 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 | — | — |
| 100% ForetriangleI × J ÷ 2 | 2.9 | 0.3 |
| 150% GenoaTypical light-air headsail | 4.3 | 0.4 |
| Storm Jib~50% of foretriangle, high-cut | 1.4 | 0.1 |
| Symmetric SpinnakerEstimated from I, J | 10.3 | 1.0 |
| Total Working Sail AreaMain + 100% foretriangle | — | — |
Foretriangle Diagram
Scale diagram unavailable — I, J, P, and E measurements are not all published for the San Juan 21 2.
Performance Ratios
How the San Juan 21 2 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
32%
Typical cruising ballast — balanced stability underway.
Typical Sail Inventory
What San Juan 21 2 owners usually carry and what's worth buying used vs. new.
Mainsail — ft²
Dacron cross-cut with 2 reef points is standard. Full-batten is a common upgrade.
Replace new
150% Genoa 4.3 ft²
The workhorse headsail. Most boats have one on a furler by now.
Replace new
110% Working Jib ~3 ft²
Good secondary sail for breezy days — used market is strong.
Buy used
Storm Jib 1.4 ft²
Bright orange recommended. Rarely used, hard to justify new.
Buy used
Asymmetric Spinnaker ~10 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 San Juan 21 2 — Dacron, laminate, and cruising performance tiers.