Turbo sailing, using your staysail
More and more on the race course we are
seeing staysails becoming increasingly prevalent again. Once upon a time the
staysail was a very popular sail. In the days of the RORC rule in the late 60’s
it was commonplace for every serious racer to have a reaching rig of
overlapping staysail and a series of yankee’s for different wind conditions. In
the IOR days that followed there spawned a whole range of “under the spinnaker”
style staysails, mostly sporting ridiculous names; Tall Boys, Lazy Boy’s,
Golden Dazy Staysails and even the ubiquitous Blooper and numerous others as
all sorts of combinations and rigs were tried.
As the IMS and later the IRC rules came along,
the staysails narrowed down to two main groups, sensibly called the Spinnaker
Staysail for off wind work and the Genoa Staysail as the name implies for
closer to the wind.
The use of these sails requires a lot of
thought and attention, if not used correctly they can slow a boat down drastically,
but when used acceptably they provide a real turbo effect. They do however require
constant monitoring and attention. Far too many times people assume they are
simply a sail you just hoist and think the extra area will do the job, like any
sail they need to be trimmed and if left alone can be extremely detrimental.
Spinnaker
Staysail
The design of the spinnaker staysail is
critical, most staysail are usually high aspect sails and as such need to be
sheeted further forward than most lower aspect sails. Another factor in the
profile of your staysail is the length of the spinaker pole or bowsprit as this
will have a direct effect as to the desired location of your tack point, the
longer the pole or sprit the further away the spinnaker will fly from the
mainsail so the proposed staysail tack attachment point can go further forward,
without the staysail blanketing the spinnaker. Conversely the position should
be located closer to the mast on a boat with a shorter sprit or pole.
Setting
up
On a lot of older boats where there is a
toerail running the full length of the deck and it is quite easy to find the
most beneficial spot to sheet home a spin staysail. On most racing boats
however the luxury of numerous sheeting positions is not an option so the
configuration or profile of the sail must be tailored to meet an existing structural
point. This sheeting position should be as far outboard as possible and ideally
close to the point of maximum beam; the spinnaker brace block location is often
ideal. This outboard sheeting gives us better control over the twist in the
staysail and more control over our leech proile.
Trimming
The main issue in a slow spin staysail is over
trimming, you never want to over trim any sail but with the spin staysail it is
a big no. When you over trim you stall the sail and this creates a vacuum
between the spinnaker and the staysail which disrupts the airflow over the
spinnaker and slows it down. Remember spinnakers do have air flowing over them
and are not just catching wind.
To this extent it is fine to sail with a
little more twist than usual, a little spillage up high is ok, a little under
trimmed is much better than over trimmed. I always ask for the sail to be set
just on the edge of luffing and no more; keep easing it all the time to ensure
it is not choking. The staysail plays an important role in that it helps
accelerate the flow over the back of the mainsail, this allows you to sheet the
main on slightly harder and helps open the slot between the spinnaker and the
main, particularly with assymetric spinnakers where the apparent wind is always
being pulled forward. This in turn allows more projection of the spinnaker and
more power. On the other hand a heavily under trimmed or flapping staysail will
cause drag since it is not driving or pulling that and that is slow also. Wind
sheer (twisted wind) will also be a major factor in the slot between main and
spinnaker; so you may want to consider setting up a barber hauler so you can
trim the sail more to the wind angle of the moment. The staysail is a very
under rated sail to trim and although small is probably the sail that can cause
the biggest problems on the boat trim-wise as it needs to be set between two
other sails and not disrupt either. Therefore it is necessary to trim with as
much aggression as the spinnaker itself, it is not a sail to be left alone, and
the general trimming should work in concert with the spinnaker.
Whenever a spinnaker luffs and collapses,
release the staysail sheet, it can retard the recovery by sucking the collapsed
spinnaker in behind it. This will make life a lot easier for your spinnaker
trimmers.
The spinnaker staysail is best kept on a
furler; it can be set up and unrolled at leisure. It needs to be rolled up for
a gybe and in the case of a symmetric dip pole gybe brought back to the mast
and then taken forward again. When gybing an assymetric spinnaker we have to
collapse the spinnaker and reset it, so as mentioned earlier we don’t want it
setting under a collapsed spinnaker so don’t unroll it until the spinnaker is
full and drawing. Use your boat speed and target boat speed for an indication
of when to redeploy the staysail after a gybe. The faster the rate of
acceleration, the earlier you can set, the slower the rate the later, as a
general rule always hold until you are up near target speed.
When using a spinnaker staysail under a symmetric
spinnaker as the wind goes further aft and the pole is brought back to
accommodate it, it is an advantage to move the staysail off the centreline and
onto the windward rail out from behind the encroaching wind shadow of the
mainsail.
When
and why
There are general rules of thumb when
staysails begin to work and in lighter winds that swirl around the rig and
sails they can clog up the area between the mainsail and the spinnaker. They
usually begin to function positively at around 11 knots true wind speed.
However it varies enormously from boat to boat, so the easiest way to find out
where it kicks in is to simply fly it and look at the boat speed, or set up and
sail with the spinnaker as per normal and then deploy the staysail, remember it
should be hoisted on a furler and ready to go. Then watch your angles and if
you have trouble with a slightly unstable spinnaker then refurl it. You will
always need to sheet the spinnaker on a touch harder when the spin staysail is deployed;
it’s just a matter of how much harder you have to sheet it on before the
performance starts to suffer. High performance boats sometimes get away with
using staysails successfully in down around 7kts, but that is something that
the team and trimmer need to monitor and decide if it is worth a try, sea state
will also come into play in the lighter conditions, bouncy conditions make it
harder to trim and control.
Remember when monitoring the speed the
spinnaker staysail will not really make the boat go faster, it will however
help with keeping a better average speed and and a result really help with vmg.
The Genoa
What we are trying to achieve is a venturii
effect between the mainsail and headsail, acting as an accelerant, a well trimmed
Genoa Staysail when used correctly can be very effective in this way.
Setting
up
The Genoa
Setting up the Genoa
I find the best way to view a Genoa
Staysail is from well aft looking up at the two sails flying, using the twist
angle to keep it in the middle of the slot between the main and headsail, when
trimmed perfectly it should be a slightly shallower mirror image of the
headsail leech profile. Note: every time the headsail is trimmed considerably,
so should the staysail need attention to keep this slot bisection even.
When
and How
The Genoa staysail begin to come into its own at about 8 knots
true on most boats, and can be used a long way up the range, so it needs to be
built a bit heavier than other staysails. In heavy conditions it will help
balance the boat out by taking some load off the helm and make the boat more
controllable in long reaching conditions.
As this staysail is used with the wind
angle a lot further forward, it is important to keep the luff as taut as
possible, we do not want the leading edge sagging into headsail area and
closing up that all important slot. It is best flown with webbing luff loops
laced onto a high torque rope, haul up the high torque rope on a Genoa
Alternative
As mentioned earlier, the Genoa Staysail is
a very similar to a conventional headsail in appearance and trim, if you do not
have one in your wardrobe and do not see the need where you would use one on a
regular basis; i.e. you mainly race short courses, it is possible when
confronted with the occasional long reaching leg to use an existing smaller
sail like a number 4 or a storm jib in this role. Just check with your
sailmaker to make sure the luff finish is strong enough to fly unsupported.
So with a staysail make sure you have done
all the experimenting and setting up prior to the day when you decide you might
use it; the racecourse is not the time to be experimenting with sheeting
positions and whether the use is feasible or not.
Use your staysails wisely and attentively,
they can make a difference and give you a little turbo boost that may make a
difference on the score sheet.
Tony Bull
Bull Sails
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