Not a small headsail — a piece of safety equipment with a different job and a different construction. The decision that matters is not how it is cut but how it gets set, because that is what decides whether it is usable when the time comes.
Why rolling the genoa away is not the answer
A genoa rolled down to storm-jib size is a bag. The fullness built into the sail has nowhere to go and ends up in what is left flying, so you have made the sail smaller and more powerful. A foam luff improves this and does not solve it at extreme reductions.
Three other things go wrong at the same time. The remaining sail sits high up the forestay rather than low and central, which drives the bow down and makes the boat hard to steer. It flogs, and flogging destroys sails fastest at the moment you can least afford it. And it is all on the forestay — if the gear jams or the sail unrolls itself, you have a large sail out in a lot of wind with no easy way to get rid of it.
What one is
Small, flat, cut high so the foot clears breaking water, and built well above what the area alone would suggest — heavy cloth, substantial corners, oversized rings and webbing.
Normally bright orange, because it is also a signal.
And designed to be set by people who are tired, wet and hanging on, which drives more of it than the shape does.
How it gets set
Settle this first. On a hanked boat it is simple: the working jib comes down and the storm jib goes up on the same stay. On a furling boat there are three arrangements:
| An inner forestay | A separate, usually removable stay behind the main forestay. Often the most robust: the genoa stays rolled, the storm jib hanks to its own stay, and the sail sets lower and further aft. Needs the stay, a strong deck fitting and a way of tensioning it — a rigging project |
| A luff sleeve over the rolled genoa | The storm jib’s luff wraps around the furled headsail and hoists on a spare halyard. No extra rigging, and the common answer on cruising boats. The sail sets outboard and higher than ideal, and getting the sleeve on over a rolled sail is real work |
| A second groove in the furling foil | The storm jib hoists in the free groove while the genoa stays rolled on the other. Works well, and only if your foil has two grooves — many have one |
It has to be decided when the sail is ordered, because it changes how the luff is built.
Two things worth doing
Hoist it on a calm day, exactly the way it would be set for real. An hour answers the questions that matter: whether the sheets reach, whether the halyard is long enough, whether the pennant is the right length, whether the sleeve goes over the rolled genoa, and whether everything needed is aboard.
Stow it somewhere reachable. Its own marked bag, with its sheets and pennant, not at the bottom of a locker under the fenders.
If you race offshore
Offshore racing rules set requirements for storm sails — maximum area against the foretriangle, colour, attachment and stowage. Tell us which rule before the sail is designed; the requirements are specific and they govern.
Configuring this at SurgeSails
Configured as a headsail with heavy-weather intent. Tell us in Design Note how the sail will be set — inner forestay, luff sleeve, or second foil groove — and whether an offshore racing rule applies. Photograph the inner stay and its deck fitting if you have one.
Cloth, corner construction, reinforcement, pennant length and colour follow from the boat and the arrangement.