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A good article on trimming the staysail a must read!

September 2, 2008 on 5:17 pm | In Uncategorized | No Comments

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.