First impressions of the Helix Furling Gennaker - Purpose built for cruising
by North Sails 3 Aug 2021 15:00 UTC
Helix Furling Gennaker © North Sails
North expert Bob Meagher gives his first-hand experience and explains why you should consider adding this sail to your cruising inventory.
I've been fortunate to serve hundreds of cruising multihull sailors in the past 20 years, often with downwind sails designed to eliminate the terrible feeling of performance loss when these boats bear away under mainsail and genoa. Apparent wind, boat speed, and the sense of freedom all plummet when the upwind sail plan just can't make the boat go past a certain point, and you can almost hear the engine key whispering, "turn me!"
Most owners have learned how cruising Code Zeros offer very convenient " beam reaching" performance but require larger-than-zero asymmetrical spinnakers for sailing deeper angles. I was always happy to offer two sails to cover wind angles from close reach to broad reach/run. And while this is still the best choice for those wishing to have optimum performance over the greatest possible wind range (ie. long-distance cruisers), I'm honored to have been part of the North Sails development team for a new "single-sail" solution - the Helix Furling Gennaker. I've experienced the Helix Furling Gennaker on various catamarans, from high-performance cruising McConaghy 60 to a more traditional Lagoon 46. I have been thrilled to learn its benefits and satisfied with its inevitable limitations.
At the dock, you'd think you're looking at a Code Zero. It lives up, and furled, on the bowsprit or bow, ready to deploy. Looking more closely, you see a very tight roll in the top third, an area where other Code Zeros can roll too loosely. Unlike standard Code Zeros, North designed the Helix Furling Gennaker to roll from the top-down, not the bottom-up, eliminating a loose furl toward the head that tends to catch the wind and sometimes even shake loose in a big breeze. And once unrolled and sailing, other differences compared to a Code Zero become clear.
A cruising Code Zero has a straight luff, supported by a thick (12mm - 19mm) cable in a sleeve up the luff, and a relatively straight leech, approximating a Genoa, but fuller. The Helix Furling Gennaker is cut more like an asymmetrical spinnaker, with a curved, forward-projecting luff and a rounder leech, resulting in a deeper sail, but one carefully designed to strike a balance. It has a very light, skinny, and flexible (8mm - 10mm) anti-torque cord running along the luff - but this cord has to carry only about half the load of an old-style luff cable. The sail itself features a structured luff to shoulder the other half of the load; allowing this lighter, smaller diameter cord to do a superior, trouble-free, job of top-down furling. When sailing closer to the wind, the halyard is tensioned tight like a Code Zero, enabling apparent wind angles of 70 degrees or a little better. The boat will perform exceptionally well when the sail is used like a traditional reacher (though the added shape in the sail does make it look a bit "knuckle-forward" when in Code Zero mode). It's when you turn downwind that the real magic happens.
Our goal was to make a sail that can point and perform like a Code Zero, and furls easily like a Zero - but with a significantly deeper downwind range. Bear off with the sail's luff pulled tight and the sail suffers from the exact thing Code Zeros do: it ends up blanketed by the mainsail, and power is lost. But this isn't a straight-luffed Code Zero - it's an especially agile Gennaker, whose superpower activates when easing the halyard and sheet. Easing the halyard, so the sail takes its "spinnaker" shape, transforms the luff into a large, positive curve, deepening the center of the sail. Easing the sheet simultaneously allows the whole sail to rotate to windward, capturing more breeze, undisturbed by the mainsail. What was previously a beam-reacher just became a powerful broad reaching sail. If you want to sail even deeper on a cat, you can move the furled sail to a pad-eye on the windward hull and unroll it there, gaining another 10-12 feet of windward projection.
We've sailed deep and stable to 125-130 degrees apparent wind angle (about 160 degrees true wind angle) in 18 knots of true wind speed. We didn't need to sail above 90 degrees AWA in that much breeze because at that angle and higher, the main and genoa drive the boat just fine. When sailing deep with the halyard eased, the head will have a mild tendency to move around a bit. We experimented with achieving the same luff projection by allowing the tack to raise, but this meant allowing the furler itself to rise to maintain furling ability. It doesn't make sense to have the furling unit bounce around two to three feet up in the air.
Furling the sail does require a bit more attention than furling a cruising Code Zero. The thumb-thick cable in a code zero is always pretty tight, and it's a skinny sail without much roach in the back, so furling a Zero can be almost as simple as a genoa (as long as you take care to not let it get too loose up top). With the Helix Furling Gennaker, the halyard should be re-hoisted fully, if it had been eased for broader angle sailing. A firmer halyard/cord transmits torque to the head better, and even more critically, a loose cord could be damaged if it kinks at the bottom when furling. Simple advice: get it tight before starting the furl. With larger sails of this type an electric winch is almost mandatory - not because there's extreme load on the furling line, but due to the much greater number of rotations needed to furl a top-down system versus a bottom-up. Finally, unlike a straight or hollow-leech code zero, there's more area toward the leech of a Helix Furling Gennaker, so you will want to keep an eye on the leech to ensure it furls without folding under or over on the way into the roll. If it does, stop furling and trim a bit of sheet — it will unwind some of the sail, and you can ease it back and try again. Learning the relative sheet tension to use when furling takes a time or two, but it's pretty straightforward. And remember, if you're furling in a hurry, ignore "neat and tidy" and just roll it up if you need to get the sail away.
By far, the most gratifying successes of these sails came after I left the boat. All these owners sail with few crew - usually it's just a couple enjoying their retirement, not interested in hassle. Following up with each of my clients some weeks later, I was thrilled to hear that the sails worked as well for them as they had during our trials. They remembered to tighten the luff before furling, had determined the ideal sheet tension when rolling the sail in, and were already playing with relative luff tension at various points of sail to get the most out of the sail. For each, gone are the days of struggling to get a large asymmetrical up out of a bow locker, or going forward in too much breeze to struggle with a snuffer sleeve on a pitching deck. Instead, the Helix Furling Gennaker offers a single-sail, from-the-cockpit solution, for sailors wanting more power. This is a terrific new sail type for a wide array of different boats around the world.