When would I use a Code Zero?
Light air upwind when your apparent wind angles are greater than 30 degrees and up to 15 knots cracked off the wind, 30-55 AWA, generally on longer distance races.

Will it work on my boat?
If you set the Code Zero from the forestay intersection of the mast your rig should handle the loads fine, but if you set the sail from any where else you should check with the spar manufacturer.

Click here for information on sail graphics. 

White = Genoa                                              

Blue = Full Asymmetrical

Red = Code Zero

Code Zero Trimming Guide
The Code Zero is a remarkable sail when properly set and trimmed. This short trimming guide is meant as a Code Zero primer.

Code Zero Range: 38 - 55 AWA & 0 - 14 AWS

The Code Zero is the smallest asymmetrical spinnaker allowed by the IRC/PHRF rule, 75% mid leech to mid luff. This is a specialty sail generally built out of high modulus materials for light air cracked off to close reaching. Properly set, this sail will dramatically increase your boat's performance as long as it can be trimmed as specified below.

The sail is designed with a straight luff and MUST be set with a straight luff. Thus, you will need the following installed on the boat. A Vectran halyard (no creep), a tack location capable of holding the mast up. It's very important to keep the luff of the Code Zero straight. If the luff of the sail sags too much, the sag will reduce the sails shaping and cause the sail to invert and possible flog as the breeze increases. Most boats will not be able to generate the luff tension necessary for this sail just by grinding the sail up. One technique is to ease the backstay all the way off. Then grind the sail up as tight as possible, then apply backstay tension to tighten the luff. If proper halyard tension cannot be achieved on the boat then an APR 75 might be a better sail.

Trimming the sail is also critical. A spinnaker sheet should be led through a tweaker block attached to the rail in the general location where a 150% genoa would trim, and back to the spinnaker turning block. The tweaker block should be used to pull the leech of the sail down. If the leech of the sail collapses and a vertical line forms from the clew to the head, the tweaker should be slightly eased. Most of the time some tension is needed on the leech line and some small cupping of the leech will occur.

The Code Zero is such a break through sail because of the profile shape. It's has an elliptical profile and generates most of it power in the upper half of the sail. Thus the foot of the sail is actually quite a bit smaller than a spinnaker. The chord depth of the sail is also quite a bit shallower than a spinnaker, and similar to a genoa. Thus if the boat is over 35' Doyle recommends a 3.0 oz. mylar film-based material and if it's over 40' a 3.0 oz. Aramid or other high modulus-based material.

For more information or to order a Code Zero, contact:

Doyle Buzzards Bay

Bill Ribar
278 Elm St.
South Dartmouth, MA 02748
   T (508) 992-6322    

T (800) 94-DOYLE

F (508) 990-2858

   buzzardsbay@doylesails.com