Start with the boat and the job. A Code Zero is a specific answer to light-air reaching, not a general replacement for either a genoa or a gennaker.
Select the boat
Choose the exact model, year and rig where they are known. The configurator records Boat Model, Boat Name and LOA, and a matched boat record provides the starting rig data for review.
If the boat has more than one rig, or its bowsprit, masthead or sail plan has been modified, identify that in Note.
Define the job
A Code Zero works between a headsail and a gennaker: a large, comparatively flat sail for reaching in light air, typically around 40-90 degrees apparent. It is useful for light-air passages and reaching legs where the headsail is too small but a gennaker will not hold its luff.
The current Code Zero configurator does not have a separate Usage field. Describe the intended wind range, angles and whether the sail is for cruising or racing in Note. Where a rating rule matters, state that here as well.
Confirm that the boat can carry it
Three parts of the boat matter before the sail is configured:
The tack point must be ahead of the forestay, normally on a bowsprit or a purpose-built fitting at the stemhead.
The halyard must exit at or near the masthead, ahead of the forestay, and must be capable of applying and holding substantial luff tension.
The rig and deck gear must be suitable for the load at the masthead, tack point and sheet leads. Whether those parts are strong enough is a rigging question to resolve with a rigger or boatbuilder.
What to photograph when the boat record is not enough
- The bowsprit or stemhead from the side and above, including the tack fitting.
- The masthead and the Code Zero or spinnaker halyard exit.
- The aft sheet leads and any tweaker arrangement.
- An overall side view of the boat and rig.
Once the boat is suitable, identify the equipment the sail must connect to in Cable & Furler.