Code zero sail

A code zero was developed in the Whitbread around the world race. In light weather, for example, a spinnaker (especially downwind) or a gennaker (reaching) is typically used. However, these are lightweight sails made of Nylon and less suitable for higher angles to the wind. For higher angles in light weather, one could use a very large genoa, but that would heavily impact the boat’s handicap. Additionally, it would require a sail change. The code zero is essentially a hybrid between an asymmetric spinnaker (gennaker) and a large genoa. The code zero has a flatter profile than a gennaker and a straight luff, making it easily used with a furler/roller. Furthermore, it is interesting that the code zero is classified as a flying headsail in the ORC rating (if the SMG > 75% of the foot length), which is more advantageous than a large genoa.

Rolly Tasker Sails builds Cruising Code Zeros to give extra performance in light winds in particular for modern boats with non overlapping genoas.

Cruising Code Zeros are designed with straight luff incorporating an anti-torsion rope and a small positive roach for stable trim and easy handling. They can be built out of heavy spinnaker cloth, which is most competitive, or a laminate for more demanding cruising sailors.

Race Code Zeros are built out of Dimension Polyant CZ Laminate. The mid girth of Racing Code Zeros is designed to be 75% of foot to avoid rating penalties which does mean a small downturn in wind range and handling but this is accepted by racers because of the advantages in rating.

A code zero is almost always flown on a special furler. These are typically flat drums with an endless line. This is then attached to the bow fitting or even better, to a bowsprit. There is a choice between an anti-torsion line in the luff, allowing the sail to be rolled bottom-up, or a so-called cable-less luff where a top-down furler is used. We would be happy to advise you.

Since the luff tension of a code zero must be significant, you should always first check if the bow fitting or bowsprit is sturdy enough to handle a code zero.