CREASES
As a sailmaker, I am keenly aware that in order to sell sails I must do two things. I must
persuade the best sailors to use my sails, and I must make sails that not only go fast,
but look good. So what am I supposed to make of the photo of Daniell Gooyer crossing the
finish line in the Championships at Torbay this summer, with a sail which if seen in the
Regatta fleet would be dismissed as rubbish?
The coaches tell us that sails should be smooth so that the wind can flow over them with
the minimum of turbulence and a sail that sets like a ploughed field is bad news.
But we can’t dismiss Daniell’s sail as rubbish because when the picture was
taken he was recording his second best result in a championship series where he trounced
this countries finest! Daniell is a member of a very professional squad which this year
produced the World Champion. Just what is going on here? Why hasn’t Daniell’s
coach taken this tatty rag away from him, burnt it and given him a respectable sail which
looks right? Perhaps Daniell is playing games! Could it be that he’s so much better
than the Brits that he can beat us with any old blanket powering his boat? Well no.
Daniell is good, but he’s not that good. Other pictures show Daniell’s sail
setting just as well as anybody else’s, but in different conditions.
Daniell is adjusting his sail settings to suit the conditions and the way he sails his
boat. 
In the picture the boat is upright and is being sailed hard and fast down
the back of a wave and Daniell is sitting hard out over the side. If he had any more power
in the rig he would have too much and would not be able to sail as fast, so he has
de-powered the rig by easing the sprit control. If the sprit was tightened up, those
ghastly creases would disappear, his sailmaker would probably be smiling, but Daniell
would have to compensate by pointing higher and not going as fast.
The message from this photo is therefore blindingly clear. Don’t set your sail to
please your sailmaker, or to look good in photos., or to impress your friends ("You
can’t possibly win with that **** sail") or to your parents ("I can’t
believe I’ve spent all that money for a sail that looks like THAT"), but learn
how to set your sail for maximum speed in different wind strengths in different wave
conditions, on different points of sailing. This means spending a lot of time on the water
practising and experimenting with different settings. You have to use the same sail in all
conditions during a regatta. The sail should not look the same in all conditions if you
want to go fast.
How many of you know someone (perhaps you) who sets the sail up on the shore exactly the
same way every time , usually by making sure that the kicker is bar tight, and then
hanging a parent on the sprit control to make sure it’s tight enough. THIS WON’T
DO! The sail must be carefully laced to the spars before going afloat, and some decisions
such as how tight to lace the luff of the sail to the mast should be made on the shore,
but the important adjustments such as outhaul, sprit and kicker must be done on the water,
in the vicinity of the start and the fittings must be in perfect working order to achieve
this, especially the cleats and the ropes which the cleats grip. One of the most important
things to practise when training is adjusting the rig on the water, and especially when
racing. Because of the sadistic fittings rules this is difficult. (I’m convinced that
whoever wrote them has never raced a boat and hates children). However the top sailors
manage to do it, so it’s necessary to learn what has to be done and practice how to
do it. If you lose 5 places every time you adjust the sprit, then obviously it
doesn’t pay to adjust the sprit, but if you find a way of doing it without losing
speed, then it will pay.
How do we know if the sail is set correctly? Well, creases are a dead giveaway, and
together with the telltales are the sails visual messengers.
The second picture shows another fast sail exhibiting creases which are regarded as
acceptable when sailing to windward in a moderate breeze. These are small horizontal
creases near the mast, and shallow creases between the clew corner (end of boom) and the
inner end of the bottom batten. What do they mean?
The creases by the mast show that the luff (leading edge) of the sail has not been pulled
tight This allows a fine entry to the leading third of the sail which helps the boat point
up into the wind and is desirable in all but very windy conditions, The creases from the
clew are because all the weight of the wind in the sail is concentrated on this corner.
There are only two ways to eliminate these clew creases completely from an Optimist sail.
One is to use a heavy stiff cloth which would not be suitable for making a responsive
adjustable sail. The other is to make a sail where the stresses are taken down the leech
of the sail (the trailing edge) and this would give a tight leeched sail which would be
slow in most conditions.
If there is a deep crease from the clew to the middle of the mast which does not disappear
with a tight sprit, or, by tightening the luff, there is not enough shape in the leading
edge of the sail and can be corrected only with a stiffer mast or a recut sail.
If there is a deep crease from the clew to the top of the mast, the sprit is not tight
enough. This crease tells you how much power you have in the rig; the bigger the crease
the more you are depowering the sail.
Bob Suggitt - Suggitt Sails
The following diagrams show common creases and what they are saying about the sail.
Sail is depowered. Tighten sprit to increase power and remove
creases.
"Fast" creases found on most well set
sails, indicating a well set up sail for moderate conditions.
Sail does not have enough shape in luff.
Sail is depowered. Loosen sprit to increase power and remove
crease. Commonly seen downwind.
Sail is depowered. Suitable only for survival conditions. To
increase power, ease outhaul and raise boom tack.
