For years, the Code Zero, a flatter, more triangular-shaped sail for close reaching, has somewhat circumvented rating rules. Designed to fit within measurements for boats with non-overlapping genoas, the Code Zero measured in as a relatively narrow, flat spinnaker that could essentially be almost three times the size of a non-overlapping jib, whilst attempting to maintain a similar shape to a reaching genoa.

However, this is set to change due to new rating rules from the Offshore Racing Congress (ORC). Amongst the summary of changes for 2020 that emerged from the Annual General Meeting of the Offshore Racing Congress (ORC) held in October last year was that; “For asymmetric spinnakers with SHW/SFL in range of 0.75 – 0.85 aerodynamic forces are calculated with both coefficients for the spinnaker and for the headsail set flying with one giving faster boat speed taken as final.”

What this essentially means, is that the new rule does not make the 75% mid-girth Code Zero illegal under the ORC rules but what has changed is the aerodynamic evaluation of such sails. This is an effort to more accurately reflect their performance and as a consequence could result in a potential increase in rating for boats carrying such sails, which might lead to a different approach going forward.

The release of the updated Velocity Prediction Program (VPP) by the ORC in January has allowed test certificates to be run and the full extent of the rating changes to be assessed. The changes are not inconsequential! In the recently completed Rolex Sydney-Hobart Race a very well placed TP52 had an elapsed time of approximately 57 hours. Under the new VPP the “penalty” for carrying the Code Zero would be an additional 40 minutes or about an 0.847% increase on corrected time. Of course, to not have the Code Zero onboard for a coastal or long-distance race has the potential to diminish performance and the question is whether the existing 75% mid-girth Code Zero is the best approach under the new VPP.

Sail selection chart comparing typical Code Zero, A1 and A1.5 use against the region (green) that the ORC VPP has considered the 75% mid-girth.

So, what does this mean for the future of the “Code Zero”?

There are a few points to consider as we move forward.
• Many boats have a 75% mid-girth Code Zero in their sail inventory and they have proven very effective performance-wise. These sails will not disappear overnight with the rating change.
• The ORC aims to be accurate with their ratings and have consequently adjusted the VPP. It will be interesting to assess the accuracy of that adjustment out on the racecourse.
• In the meantime, sailmakers and sail designers, such as those at Ullman Sails, will be having a very close look at how to minimize the “penalty” for carrying a Code Zero style sail under the new rule.

Finally, Ullman Sails sail designers, working under other rules such as the USA ORR rule have already been striving to produce flying sails that whilst not able to circumvent the new ORC rule do offer an alternative approach that may prove useful. Interesting times!

* Since publishing the ORC has modified the VPP, something they have the right to do, particularly in the early part of the year. The update to the VPP sees the “penalty” noted in the article drop from 0.847% to 0.584%. There is still a price to pay and the question remains as to whether the existing 75% mid-girth Code Zero is the best approach under the new VPP.