S2 7.9 Sail Configuration Guide

Overview

The S2 7.9, designed by G&S, is a versatile and highly successful racer-cruiser known for its performance-oriented fractional rig and trailerable convenience. It targets competitive one-design sailors and enthusiasts looking for a weatherly boat that balances speed with weekend comfort.

Rig Specifications & Performance Analysis

Detailed analysis of the G&S rig dimensions reveals a well-balanced sail plan:

• Mainsail Configuration: A P/E ratio of 2.41 indicates a moderate-aspect rig, providing a powerful mainsail that serves as the primary engine in most conditions.
• Foretriangle Design: The I/J ratio of 3.21 indicates a tall, narrow foretriangle, which is highly efficient for high-aspect jibs and allows for significant overlap with large genoas in light air.
• Sail Area: With 30m² of total upwind sail area on a 7.89m hull, the boat maintains a competitive power-to-weight ratio.
• Performance: The configuration is heavily weighted toward racing performance while remaining manageable for short-handed cruising.

Popular Sail Configurations

• Mainsail: Standard configurations often include full top battens to support the leach and maximize the 17m² area.
• Headsail: Owners typically run a 150% genoa for light-air performance or a 100% working jib for heavy-air stability.

Key Characteristics

• P/E 2.41: Powerful mainsail plan providing excellent acceleration and light-air drive.
• I/J 3.21: High-aspect foretriangle optimized for efficient pointing and headsail versatility.
• 7.89m LOA / 1.53m Draft: Deep-draft hull design that ensures a stiff, stable platform for upwind work.
• G&S Design: Balanced helm and responsive handling characteristics typical of high-performance fractional rigs.

Sailing Considerations

• Recommended for reefing the mainsail at approximately 16–18 knots to maintain a flat profile and reduce weather helm.
• Requires 3–4 crew for optimal weight distribution during racing, though the 30m² area is manageable for double-handed sailing.
• Performance expectations include excellent close-windedness and the ability to plane in heavy-air off-wind conditions.

Sailmaking Recommendations

For the S2 7.9, we recommend SurgeX membrane sails as the optimal choice for most sailors. SurgeX uses continuous fiber construction where fibers are laid along load paths and embedded in a thin membrane, providing superior shape retention compared to traditional Dacron while being more affordable than premium laminates. The continuous fiber structure means less stretch over time, maintaining the designed sail shape for years.

For racing applications, specify a lightweight SurgeX configuration with minimal base weight to maximize performance. For cruising or weekend sailing, add a taffeta protective layer on both sides to enhance UV resistance and abrasion protection. Based on the 2.41 P/E ratio, a tri-radial fiber layout works best to handle the high loads along the leach. A typical inventory includes a square-headed or high-roach main, a 150% light-air genoa, and a class-compliant spinnaker. With 30m² of sail area, plan to reef around 16 knots to preserve the membrane's structural integrity and boat balance.

Conclusion

The S2 7.9 remains a benchmark for small racer-cruisers, offering a sophisticated rig that rewards precise sail trim. Explore sail options for S2 7.9 to maximize your performance on the water.