KER 56 Sail Configuration Guide

Overview

The KER 56, designed by Jason Ker and built by Knierim, is a high-performance racing yacht engineered for competitive offshore circuits. Its design philosophy prioritizes structural stiffness and a high power-to-weight ratio for elite-level racing and fast passage making.

Rig Specifications & Performance Analysis

• Mainsail Configuration: A P/E ratio of 3.02 indicates a high-aspect-ratio rig, optimized for aerodynamic efficiency and upwind lift.
• Foretriangle Design: The I/J ratio of 3.49 is tailored for high-efficiency, non-overlapping jibs that maximize pointing ability.
• Sail Area: 164m² total upwind area provides significant drive for a 17-meter platform.
• Performance: The 3.96m draft suggests an exceptionally stiff boat capable of carrying full sail in higher wind ranges than standard cruisers.

Popular Sail Configurations

• Mainsail: Typically a high-modulus square-top configuration to capitalize on the 23.5m luff length.
• Headsail: Setups usually include a suite of jibs (J1-J4) and reaching headsails like Code 0s to suit the 3.49 I/J geometry.

Key Characteristics

• High aspect ratio mainsail (P/E 3.02) for superior upwind velocity.
• Powerful foretriangle (I/J 3.49) optimized for high-efficiency headsails.
• Extreme 3.96m draft provides the righting moment needed for the 164m² upwind plan.
• Carbon-intensive construction results in a stiff, weatherly racing machine.

Sailing Considerations

• Requires an experienced crew to manage high sheet loads and 17.06m LOA inertia.
• The deep draft limits access to shallow harbors but offers elite stability in offshore conditions.
• Expect a very close-winded performance with high targets in light to moderate air.

Sailmaking Recommendations

For the KER 56, 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 and reduce aloft weight. For cruising or delivery legs, add a taffeta protective layer on both sides to enhance UV resistance and abrasion protection. Based on the 3.02 P/E ratio, a multi-axial fiber layout works best to handle the high vertical loads. A typical inventory includes a square-top mainsail, J2, and a J4 for heavy air. With 164m² of sail area, plan to reef around 20 knots TWS to maintain optimal heel angles.

Conclusion

The KER 56 is a masterpiece of modern naval architecture, blending a tall, efficient rig with a powerful hull. Explore sail options for KER 56 to maximize your racing potential.