Rigging Dimensions
The four foretriangle measurements sailmakers need to quote a new suit.
I ?
34.29 ft
J ?
25.90 ft
P ?
1.00 ft
E ?
39.28 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 | 19.6 | 1.8 |
| 100% ForetriangleI × J ÷ 2 | 444.1 | 41.3 |
| 150% GenoaTypical light-air headsail | 666.1 | 61.9 |
| Storm Jib~50% of foretriangle, high-cut | 222.0 | 20.6 |
| Symmetric SpinnakerEstimated from I, J | 1,598.6 | 148.5 |
| Total Working Sail AreaMain + 100% foretriangle | 463.7 | 43.1 |
Foretriangle Diagram
Drawn to scale from published I, J, P, E measurements — Cutter · Roger Macgregor design
Performance Ratios
How the Macgregor 65 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
41%
Stiff enough to carry a 150% genoa comfortably into moderate breeze.
Typical Sail Inventory
What Macgregor 65 owners usually carry and what's worth buying used vs. new.
Mainsail 19.6 ft²
Dacron cross-cut with 2 reef points is standard. Full-batten is a common upgrade.
Replace new
150% Genoa 666.1 ft²
The workhorse headsail. Most boats have one on a furler by now.
Replace new
110% Working Jib ~488 ft²
Good secondary sail for breezy days — used market is strong.
Buy used
Storm Jib 222.0 ft²
Bright orange recommended. Rarely used, hard to justify new.
Buy used
Asymmetric Spinnaker ~1,599 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 Macgregor 65 — Dacron, laminate, and cruising performance tiers.