Offshore Performance

Spider Racing Series

Bill's Spider Mainsails

The Bill's Spider Mainsail panels change direction at four horizontal junctions for precise alignment. These panels are oriented to fan from the head and the clew following the load path through the leech.

The luff of the sail allows controlled stretch for draft adjustment. Kevlar content is reduced as loads decrease in the forward and center sections of the sail. By saving weight in the non-load-bearing areas of the cloth, chafe-resistant taffetas can be added to key sections. As a result, the Spider Mainsail has increased durability while being lighter than the industry average mainsail weight.

Bill's Spider Mainsail design maximizes the efficiency of your rig. The sail is constructed with minimum luff curve to push the roach to the absolute limits of the applicable racing rule for increased projected area. Cored, tapered battens are used for to reduce weight. The specific flex characteristics of each batten match the sail shape. Rugged, sophisticated and streamlined batten pocket construction allows incremental tension control with fail-safe batten closure.

Bill's Spider Headsails

Bill recognizes the importance of building a genoa that holds its shape while wind and wave conditions change. Our proven computer shapes, combined with the strength characteristics of high-quality fabrics, ensure superior performance across the widest possible wind speeds.

Bill's Spider Headsails attain minimum weight by tapering the Kevlar content in the center of the sail, where loads decrease. This effect actually flattens the sail as the loads along the foot and leech increase with sheet tension. When designing your Spider Headsail, we pay strict attention to maximum area. The leech is engineered to give a consistent slot, compressing the airflow evenly along the leeward surface of the mainsail. This minimizes backwinding and produces the cleanest exit of airflow. The result is tighter sheeting on a narrower sheeting base which allows higher pointing with speed.

Bill's Spider Blade Jibs

Bill's Spider Blade Jib designs fill the foretriangle as completely as the rig will allow. Blade Jibs are constructed with shaped panels because the wind range required for Blade Jibs is smaller. This locks the draft forward and opens the leech, an essential shape for performance in upper wind ranges.


Bill's Spider Spinnakers

Bill employs the most sophisticated computer-molded spinnaker design system in the industry, allowing each panel to be shaped separately. These molded panels fit together without distorting the lightweight spinnaker fabric. The result is the most efficient sail for maximum offwind speed. Breakthrough shapes are engineered for performance spinnakers in any size range, from runners for the Grand Prix Maxi circuit to world champion all-purpose J 24 spinnakers.

Bill's Spider Asymmetrical Spinnakers

The Spider asymmetrical spinnaker evolved from the most extensive research and development program ever conducted on asymmetrical spinnakers. The 1992 America's Cup course, introduced only for the 1992 Cup, was the famous zig-zag course with 100 and 135 downwind angles. Bill led the research and design program based on his design program and relying on the extensive resources of the America3 Foundation. The sails were built using CFD (computational fluid dynamics) and tested on the water to determine superior shapes based on a combination of apparent wind angles, apparent wind speeds and the stability of the boat.

This same combination of information is used today to build your asymmetrical spinnaker. The resulting smooth design and correctly-sized sail with appropriate cloth choice ensure your top performance off-the-breeze. Whether you sail a J 80, a Melges 24 or other asymmetrical boat, your performance will improve with our state-of-the-art asymmetrical spinnaker.

For specific class information on Offshore One-Design Classes, please look in Bill's Sail Design.


The RaceSail Series

The RaceSail is a new introduction to paneled sails with a shape of elliptical panels. These curved, elliptical panels form an efficient vertical skeletal structure along the loadlines of the sail.

Elliptical Load Carriers Are the Secret
The elliptical load carriers in the RaceSail are smooth. They carry loads from the corners (the head, clew and tack) and load points (reef points), on the seams, not on the sail material. The radiating load carrier elliptical seams of the RaceSail eliminate the deterioration of fibers in normally high stressed areas.

The result is a sail that can be constructed of lighter material with less fabric and no horizontal joiner seam transition problems. As a result, all overlapping material is working for the strength of the sail rather than just adding weight to the sail. Shaping is distributed across the sail creating a smoother design.

Shaped Panels
Sail design is successful when the appropriate shape is achieved. This success results from design experience, creativity, inventiveness and an understanding of the manufacturing process. Paneled sails and cross-cut sails are the current most successful method for designing fast sails, much better than molded sails. But, they can limit the designer to shaping the sail horizontally.

Every panel is shaped in the RaceSail. The lack of straight lines results in a smoother, and therefore, faster shape. This design was tested computationally and extensively on the water during the winning America3 campaign. An elliptical layout for sail panels allows a sail to perform at its peak through a wider wind range with fewer adjustments.

A main attribute of the RaceSail is its efficiency. Molded sails and most panel sails have seams with no purpose but to join panels, adding weight without increasing strength or durability. Additionally, shape restoration seams are designed into the RaceSail to allow for accurate tweaking and adjustment to the sail overtime based on the amount of wear on the sail and the conditions in which it was used.

The RaceSail Series is a priority design approach for use in mains, jibs and genoas. In the future, Shore Sails will use the design theories in symmetrical spinnaker and asymmetrical spinnaker design, too.

RaceSail with Cuben Fiber The design of the RaceSail is a significant improvement in performance sails. In certain materials, though, it shines. When the RaceSail is made in Cuben Fiber, it improves the pitching moment, stability and handling of all boats and represents a significant weight reduction.

Cuben Fiber
Choosing Sails

Contact Bill Shore

Shore Sails International 2006
(401) 862-9608

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