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BLUE PAPER - Code Defined BLUE PAPER: A North Sails Guide

CODE SAILS DEFINED

The name Code Zero means Code Zeros were designed to qualify as downwind spinnakers. As the effectiveness different things to different spinnakers under various rating rules, and ease of use became increasingly sailors. What started out as a which require the mid-girth to be 75% of apparent, the Code Zero’s popularity has straightforward but innovative concept, has the foot length. Multihull sailors called expanded into cruising that benefit in evolved into an entire category of sails still these sails Screechers, while Volvo Ocean much the same way. under development. As a result, one Code Racers coined the term Code Zero - fitting Zero may look and perform quite differently below the standard coding convention When considering a Code Zero type from another, depending upon any number established by North Sails of A1, A2, A3, for your , it’s important to know your of design criteria. etc. This design then became popular target angles, wind speeds and amongst many handicap racers under handling system, so that your sail can There is however one common theme Rules like IRC, ORR and PHRF; and it be customized to your specific needs. amongst all the versions of these sails. Code remains a multihull standard. Depending upon these requirements, you Zeros are free flying, designed for close will find a wide array of purpose-built Code reaching angles, generally used between The greatest benefit of the Code Zero is Zero materials to choose for your sail. 40-90 degrees angles and adding a great deal of sail area and efficient true wind speeds under 20 knots. sail power to underpowered, close reaching Here is a rundown of some of the names angles. Boats with non-overlapping and styles of Code Zero’s which are now To understand the different names and headsails also see the biggest benefit from also commonly called Code Sails. different versions of these sails, it helps a Code Zero Asymmetric as the to look back at their origin. Originally sail fills a large gap between upwind and

BLUE PAPER - Code Sails Defined Asymmetric Spinnakers - Spinnaker Mid Sub Zero’s (SMG 50%-75%) Free Flying Genoas (SMG<50%) Girth (SMG) >75% / Reacher “Flying” sails are defined by the Equipment Code Zero Asymmetric Spinnaker Many multihull racers will recognize Rules of to be “set with no sail Used for rating rule racing, this sail a Screecher as a low-clewed, upwind edge attached to the rig.” As a result, close remains much the same in concept as the type sail that sheets inside the reaching and upwind flying sails require original Code Zero. The design brief is the upper shrouds. Some multihull rating High Modulus Luff Ropes and Anti Torsion flattest possible sail with a Spinnaker mid- rules like OMR specifically define this sail Ropes for those sails set on furlers. girth of 75%. The challenge of designing as having a mid-girth between 50%-75%. and building a Code Zero Asymmetric Cruising sailors may view this For some boats, which are not restricted Spinnaker is that the girth requirement sail as having a higher clew, fuller shape by rating rule implications and where sail restricts how flat the sail can be; these that sheets outside the upper shrouds. plan versatility is a premium, a variety of sails have unsupported sail area that is not furling headsails and spinnakers may be totally efficient in order to achieve the goal G Zero set on either bottom-up or top-down of light air, close reaching as close as 40 The G Zero is the North Sails internal torsion rope furling systems. This degrees AWA. This sail is typically made cruising version of a Code Zero. This sail is especially true in offshore racing boats, in a lightweight laminate designed is not restricted to the rating rule 75% where many of the sails called Zeros are in specifically for Code Zero applications. It mid-girth requirement and is therefore an fact upwind or close reaching Genoas by will utilize an anti torsion luff rope with easy to use and versatile sail. The G Zero design and performance. Any sail with a either top-down or bottom-up internal luff Gennaker is appropriate for both modern mid-girth 50% of the foot length is likely to rope furling. and traditional cruisers; it can be made in have a Genoa shape and be used for true a variety of materials and used with both upwind sailing. However, in practice, these A0/A3 Hybrid Asymmetric Spinnaker furlers and snuffers. sails also get used for close reaching, so This is another popular rating rule sail they are commonly and maybe incorrectly that tends to be more versatile than a labeled Code Zeros by some who use them. pure Code Zero. The shape is halfway between a Code Zero and a A! or A3. It is Masthead Zero (MHO) – Full Size, Full commonly made in spinnaker Hoist Free Flying Genoa for light air cloth and not necessarily used on a furler. upwind use. The A0/A3 Hybrid will not sail upwind Fractional Zero (FRO) – Free Flying like a Code Zero, but it can cover a wide Genoa set on fractional to reduce range of angles and conditions and sail aspect ratio and reduce heeling force. proves extremely versatile on boats that may prefer to carry fewer spinnakers in Blast Reaching Zero (BRO) – Blast their inventory Reacher set on a sprit. Sometimes used in a triple slot setup with a and .

BLUE PAPER - Code Sails Defined