Below is how Smyth does spinnaker, and it's worked for me on boats from beachcat to F-boat to Catana
written for Sailing World by Randy Smyth
It's rare in sailing when an improvement in performance can also deliver simplicity. This synergy just about defines asymmetrical spinnakers. Starting with a cross-sectional shape that resembles an airfoil, these sails
have offered a known downwind advantage for years, but their popularity has been stifled by handicap rules that have outlawed their use. Now it's difficult to imagine an America's Cup without them. Asymmetrical spinnakers are considered mandatory sails aboard everything from long-distance single-handed racers, to multihulls, to cruising boats where fun is taken seriously. Whether you sail a high performance ride or are just looking for simpler sail handling, there's no better way to turbocharge your off-wind speed.
One of the most often asked questions when people are considering an asymmetrical spinnaker is whether to use a snuffer. These full-length nylon sleeves allow controlled setting and dousing completely solo. The best type has a fiberglass
mouth at its base that smoothly and safely gobbles up even a massive spinnaker. Single-handed sailors swear by their snuffers, however, most racing
teams have found that a proper spinnaker turtle is the quickest method for course racing
. The additional step of operating the snuffer is eliminated, which allows the sail to be set quicker and flown longer before dousing at the leeward mark.
Before leaving the dock
(or beach) install three or four sets of telltales along the luff of the sail, about a foot back. It's helpful to have one set down low where they're easily visible. These will play a significant role in your management of the apparent wind. Now let's have a look at how to fly these powerhouses.
Regardless of which sail-setting method you've chosen, it's time to get hooked up. Your first decision is whether to set up the sheet to jibe inside or outside. If your boat has a fixed "bowsprit" pole, it's safer and faster to jibe with the lazy sheet rigged inside. This means that the lazy sheet will pass between the headstay and the spinnaker luff (inside the spinnaker). On boats without fixed poles, the lazy sheet should be rigged outside the spinnaker (in front of the luff). There just isn't enough room between the headstay and the spinnaker when jibing.
To set up for inside, the tack line should be over the sheet when hooking up the sail. For safety
it's best to tie the two sheets
to the clew separately. Don't attach them to a common snap shackle -- you're asking for trouble if the shackle ever opens accidentally, and it's dangerous to have a heavy piece of metal flailing around above the foredeck. Finally, attach the halyard
and you're ready for action.
Here's the Golden Rule
for setting asymmetrical spinnakers for racers and cruisers alike: Always set in the wind shadow of the mainsail
. Even if your intended course is a beam reach, the skipper
can make life much easier for the crew by steering
downwind during the hoist.
Here's the proper order for a set out of a turtle bag: Raise the halyard
and trim the tack line, then sheet in. If you're using a snuffer, raise the halyard, trim the tack line, haul up the snuffer, and sheet in. Be sure the halyard and tack line are both set and cleated before trimming the sheet.
Larger boats should be organized with the halyard and tack line controls close together. This allows the cruising sailor to operate both single-handedly. Racers will be more efficient with two people working together as a team.
If you're sailing a small, double-handed catamaran
, the best hardware
system incorporates a combination halyard/tack line, which eliminates one step when setting and dousing. Experience has shown that the crew should hoist the halyard/tack line with both hands, while the driver trims the sheet with one hand initially during the hoist.
In double-trapeze winds, catamarans and dinghies have the fastest sets with the driver on the trapeze throughout the set. Once the spinnaker is flying in these conditions, the crew trims the sheet while the driver plays the main.
Now it's time to extract the performance potential of your asymmetrical spinnaker. Apparent wind plays a vital role in cranking up the boatspeed. Unlike conventional spinnakers that operate on sheer pulling power, asymmetrical spinnakers are shaped to turn the wind and produce lift
. Technically, when used properly, an asymmetrical spinnaker can produce nearly 1.8 times the power of a similar-sized conventional spinnaker that is sailed dead downwind.
Here's a simple routine that I've used successfully on boats from the America's Cup to International 14s:
--Steer to keep the apparent wind at 90 degrees. (We'll optimize this angle later.) If you're not instrument-equipped, a masthead fly or shroud
telltales work well.
--Adjust the spinnaker sheet until the leeward telltales are flowing.
--Steer by the telltales, maintaining a constant apparent wind angle.
--Adjust the jib
sheet for proper telltale flow (more on flying the jib later), but keep steering
by the spinnaker telltales.
--Make sure your main is optimized for maximum power by overtrimming the sheet until it stalls, then easing out slowly until the leeward telltales just begin to flow.
Now the driver can steer by the spinnaker luff telltales and the whole sailplan is tuned for the apparent wind angle (in this case 90 degrees). Simple, isn't it? Why 90 degrees? That's the tricky part. Every boat has a different optimum apparent wind angle for it's best VMG downwind. For the America's Cup catamaran
, the apparent wind was best at 28 to 32 degrees while screeching downwind on one hull
. F27 trimarans are optimized with the asymmetrical spinnaker and fixed pole at 90 degrees apparent. International 14s perform best at 90 to 100 degrees in planing conditions. Finding the elusive optimum apparent wind angle is similar to finding the optimum angle to sail upwind. Instrument packages that output VMG will get you close, but sparring with a similar boat will always answer this question best.
The technique of steering by the asymmetrical spinnaker telltales not only wins races but greatly reduces crew fatigue. While conventional spinnakers require the sheet to be trimmed nearly nonstop, asymmetrical spinnakers simply require an attentive driver.
Just remember that all your sails are trimmed in unison for a given apparent wind angle. If the leeward spinnaker telltale stalls it means that the jib and main are also stalled. When this happens your lift
diminishes dramatically. The driver should head
up quickly until the leeward spinnaker telltales regain flow. When you're looking for more power, a great technique is double-slotting. Whenever the apparent wind is less than about 100 degrees, (and this is usually the case when reaching in a multihull
or fast planing dinghy) a jib can be quite effective when used with an asymmetrical spinnaker. If you have a fixed pole and it's over half the length of your foredeck, you're a candidate for double-slotting. The jib gives you a double advantage -- more sail area and increased the circulation around the mainsail
. This provides attached flow on the leeward side of the main for increased efficiency. On non-rotating masts this is a very effective way to smooth out the turbulence caused by the mast
So much for creating maximum power. What about depowering? Here the answer is the same for both multihulls and monohulls. In heavy air, safety
is found by choosing a larger apparent wind angle. In other words, trim for a more downwind course. When reaching in puffy conditions, always release the mainsheet first. This creates leeward helm
, which automatically helps steer the boat downwind (even if your rudder
is in the air or cavitated). Only release the spinnaker sheet as a last resort.
Fine-tuning of the asymmetrical spinnaker luff will help make it user-friendly. If your spinnaker collapses without warning, it probably has too flat an entry. An easy cure is to tighten the halyard, which will round out the entry. However, if your spinnaker has a perpetual curl in the luff, it's time to ease off the halyard a bit to flatten the entry.
Here's where the simplicity of the asymmetrical spinnaker really shines. Setting up for a jibe is easy -- no one even has to leave the cockpit
. Just make sure that the spinnaker sheets
are clear. As in most maneuvers, communication is an important element in executing consistently smooth jibes. To initiate the jibe the driver should let the crew know when the jibe is started. This alerts the spinnaker trimmer to ease the sheet slowly to keep the sail filled as long as possible during the turn. The object is to let the spinnaker "float" forward and allow it to pass to the new side without catching on the headstay. It helps to steer a smooth, wide arc
. We're talking slow turn.
When the spinnaker starts to droop in the mainsail's wind shadow, the trimmer fully releases the old sheet and trims in the new one. During this portion of the jibe, the driver can speed up the turn to help the spinnaker "snap" full on the new jibe.
Final trimming is a repeat of the apparent wind routine: Steer to the apparent wind, adjust the spinnaker sheet, then adjust the jib. At this point I use the mainsail as a report care. If the mainsail's leeward telltales are flowing properly, you've successfully duplicated your previous jib's apparent wind angle. If they're stalled, it's time to sheet in the spinnaker for a closer angle.
Once you find an optimum apparent wind angle for your boat downwind in an average wind strength, mark your sheets. Be sure you lay both sheets side by side to mark them evenly. Use the marks as references
to work from at different wind velocities and sailing angles. This will greatly improve your downwind consistency.
All good things must end. At dousing time, the Golden Rule
applies again: Always douse in the wind shadow of the mainsail.
If you're using a snuffer the order goes like this: Release the tack line, pull the snuffer sleeve over the spinnaker, then release the halyard. The sleeve is gathered to leeward just forward of the boom, near the mast
in the mainsail's wind shadow.
For crew using a conventional spinnaker bag, dousing consists of simply releasing the tack line, then easing the halyard as the sail is gathered (in the mainsail's shadow) into the bag. To guarantee that the halyard and tack lines can't get tangled, I make it a habit of throwing their tails overboard
. Yes, it causes a bit of drag, but life is much worse when the halyard gets stuck halfway down at a crowded mark rounding. If you're anticipating another set, just leave the lines attached and you're ready to go again."