Rigging Dimensions
The four foretriangle measurements sailmakers need to quote a new suit.
I ?
42.75 ft
J ?
12.00 ft
P ?
38.75 ft
E ?
13.75 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 | 266.4 | 24.7 |
| 100% ForetriangleI × J ÷ 2 | 256.5 | 23.8 |
| 150% GenoaTypical light-air headsail | 384.8 | 35.7 |
| Storm Jib~50% of foretriangle, high-cut | 128.3 | 11.9 |
| Symmetric SpinnakerEstimated from I, J | 923.4 | 85.8 |
| Total Working Sail AreaMain + 100% foretriangle | 522.9 | 48.6 |
Foretriangle Diagram
Drawn to scale from published I, J, P, E measurements — Sloop · Gerry Douglas design
Performance Ratios
How the Catalina 309 carries its sail relative to its displacement.
SA/D Ratio
16.4
Moderate — comfortable coastal cruiser, not overcanvassed.
Mast Height (above DWL)
48.3 ft
Clears the 65 ft ICW fixed-bridge standard with room to spare.
Ballast Ratio
41%
Stiff enough to carry a 150% genoa comfortably into moderate breeze.
Typical Sail Inventory
What Catalina 309 owners usually carry and what's worth buying used vs. new.
Mainsail 266.4 ft²
Dacron cross-cut with 2 reef points is standard. Full-batten is a common upgrade.
Replace new
150% Genoa 384.8 ft²
The workhorse headsail. Most boats have one on a furler by now.
Replace new
110% Working Jib ~282 ft²
Good secondary sail for breezy days — used market is strong.
Buy used
Storm Jib 128.3 ft²
Bright orange recommended. Rarely used, hard to justify new.
Buy used
Asymmetric Spinnaker ~923 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 Catalina 309 — Dacron, laminate, and cruising performance tiers.