Rigging Dimensions
The four foretriangle measurements sailmakers need to quote a new suit.
I ?
50.92 ft
J ?
14.67 ft
P ?
44.16 ft
E ?
15.68 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 | 346.2 | 32.2 |
| 100% ForetriangleI × J ÷ 2 | 373.5 | 34.7 |
| 150% GenoaTypical light-air headsail | 560.2 | 52.0 |
| Storm Jib~50% of foretriangle, high-cut | 186.7 | 17.3 |
| Symmetric SpinnakerEstimated from I, J | 1,344.6 | 124.9 |
| Total Working Sail AreaMain + 100% foretriangle | 719.7 | 66.9 |
Foretriangle Diagram
Drawn to scale from published I, J, P, E measurements — Masthead Sloop · Gerry Douglas design
Performance Ratios
How the Catalina 387 carries its sail relative to its displacement.
SA/D Ratio
16.2
Moderate — comfortable coastal cruiser, not overcanvassed.
Mast Height (above DWL)
56.0 ft
Clears the 65 ft ICW fixed-bridge standard at normal tide.
Ballast Ratio
36%
Typical cruising ballast — balanced stability underway.
Typical Sail Inventory
What Catalina 387 owners usually carry and what's worth buying used vs. new.
Mainsail 346.2 ft²
Dacron cross-cut with 2 reef points is standard. Full-batten is a common upgrade.
Replace new
150% Genoa 560.2 ft²
The workhorse headsail. Most boats have one on a furler by now.
Replace new
110% Working Jib ~411 ft²
Good secondary sail for breezy days — used market is strong.
Buy used
Storm Jib 186.7 ft²
Bright orange recommended. Rarely used, hard to justify new.
Buy used
Asymmetric Spinnaker ~1,345 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 387 — Dacron, laminate, and cruising performance tiers.