Looked up the NZ Category 1 rules about storm sails
for 2021-24, part of which follow:
Skippers should consult their sailmaker
to arrive at the best sizes. The sizes given below
are maximum suggested sizes only and should be followed only after due consultation.
65 percent of the luff of the largest headsail (0.65 IG) and of suitable strength for the purpose. A means of attaching the luff to the stay/foil, independent of any luff groove device. Aromatic polyamides, carbon fibres and other high modulus fibres shall not be used in the storm jib
For new storm jibs made after January 1, 2010: One storm jib
not larger than 3.5 percent height of the foretriangle squared, with luff maximum length 50 percent height of the foretriangle.
must be permanently attached.
(c) One heavy weather jib
of 70 percent of the fore triangle area.
(d) All mainsails should be capable of being reefed.
(e) Mainsails shall have a set of reef points capable of reducing the effective luff by 50 percent.
All yachts equipped with an in-boom or in-mast furling systems shall be equipped with a trysail.
Storm sails designed for a luff-groove device shall have an alternative method of attachment to the stay. Trysail slides must be metal and compatible with the mast
A suitable sail repair
, toilet, ventilation, bunks, stowage, food
There shall be no area of the accommodation from which a galley
fire would prevent exit.
Toilet securely installed.
One storm trysail not larger than 12% of the mainsail
luff length x mainsail
foot length. It shall be sheeted independently of the boom and shall have neither a headboard nor battens and be of cloth weight of suitable strength
for the purpose. The yacht’s sail number and letter(s) shall be placed on both sides of the trysail OR rotating wing mast
in as large a size as is practicable. Rotating wing masts may be used in lieu of a trysail. Aromatic polyamides, carbon fibres and other high modulus fibres shall not be used in the storm trysail. All slides must be of strong metal construction and compatible with track being used.
OR if it is not practical to fit a trysail then the deep reefed mainsail shall have the luff reduced to 35 percent or less. The mainsail and reefing equipment
must be in excellent condition and be specifically designed and constructed to withstand storm conditions.
If a separate trysail track is fitted, a stop is to be fitted to the top of the trysail track.
A spare main halyard
It does not appear that they trust the r/f mains to work
in storm conditions that would call for a storm trysail. There is the "OR" section if it is not practical to fit a trysail, but it is not clear who decides about the practicality. The stipulations about the luff length, the strength/durability of the sail material and the prohibition of certain popular materials in the storm sails may prevent those with r/f mains from complying. It might simply be cheaper and easier to get a really heavy Dacron storm trysail than to try to cobble something else together that will pass inspection
. It also looks like they want to be able to identify the vessel from the storm sail. A reefed main might not show all the information wanted.