We sail, we want to sail fast, and the only thing stopping us sailing faster is drag.
Drag comes in two main forms. The hull and centreboards creates drag in the water. The Rig creates drag through the air. Water being 1,000 times denser than air by a lot, the drag created by the hull is the most important one to minimise. However, sail drag is also of importance once we minimise hull drag, so we will cover both topics in this blog.
At every stage we must bear in mind that the design of a boat, foils and rig dictate that there will always be a drag factor involved. Our goal as racing sailors is to minimise that drag. It not only has the benefits of making you faster, but reduces rig load significantly in manoeuvres, giving a double gain.
How do we “listen” to the boat and make the necessary adjustments to minimise drag?
The tiller is the direct line to what the boat wants to do. If the tiller is pulling away from you and you have to pull it towards you to maintain a straight line, its called weather helm – left to its own devices without corrective steering the boat wants to head up into the wind. The opposite, where you need to push the tiller away from you is called lee helm, and is every bit as destructive, and more, than weather helm because it destroys any height advantage that you seek, so lowering VMG.
So we’ve “listened” to the tiller. Its told us the boat wants to go upwind or downwind and needs corrective steering, producing turbulence, which leads to drag, which leads to being slow. What’s the cure?
The only way that the boat wants to steer itself away from a straight line is the simple, “beginner” knowledge, which is that the centre of effort of the rig is in the wrong place.
It is easily solved. Assuming the sails are not worn/stretched, we can definitely say that by pulling on more downhaul the centre of effort will move forward, reducing weather helm, or pulling the kicker (assuming it doesn’t bend the mast) that the increased kicker tightens the leech and moves the centre of effort backwards, reducing lee helm.
We can then begin to judge whether we need a stiffer or softer setup, or even the hardware of the mast. If, when the boat is tuned to steer straight we are underpowered compared with our opposition, we need to straighten the mast by going lighter on the settings. If we are overpowered, we need to bend it by putting more shroud tension on. Please note that on an unstayed rig (laser etc) the same principles apply in as much as the cunningham and kicker are concerned, you just don’t have the option of too many choices of mast stiffness, hence the need to be in the weight band for Laser.
At Toplevel Sailing we keep it simple, always beginning with the basics, so that our sailors truly understand the process of becoming faster.
There are other factors:
On a two sail boat, powering up the jib leads to lee helm. This is easily balanced by more leech tension (kicker) on the main. Effectively for every condition the balance of the boat is minutely different, yet also critical to that winning extra 0.1 of a knot speed.
Bow steering is usually a destructive force on the boat. If the boat is heeled, the water flow over each side of the boat becomes asymmetrical. When that happens, usually leeward heel leads to wanting to head up which is combatted by the tiller being pulled toward you, producing turbulence, and windward heel makes the boat want to bear away. Sailing close to flat, or in the boat’s “sweet spot” becomes essential, otherwise you are using sail tuning to correct an already flawed base.
Balance is everything in sailing. Learning where your sweet spots are on the rig and the hull is always felt through the tiller. Learning what to pull, when, and how to set up the mast is a process which takes even the most experienced sailor some time to achieve. At Toplevel Sailing we encourage a systematic approach, but always based on the feel and talent of our sailors.