By Vaughn Harrison via International Sailing Academy
Very few sailors excel in light wind and choppy water. It is the most challenging condition because your sail and telltales aren’t always working. You must constantly anticipate changes in boat speeds and this never allows you to get comfortable.
Even though it’s light, changes to apparent wind are constant. Subtle changes will slow the boat, stall the sail and induce leeway, making your experience miserable. In order to conquer these challenges one must learn to:
- make body movements to maintain balance
- steer to reduce drag
- sheet to the change in apparent wind direction
- set up the sail to be forgiving
The simple way of looking at apparent wind change through chop is:
- In flat spots, the boat is sailing at an optimal angle and speed for the wind condition, and the apparent wind direction is relatively forward.
- In choppy sections, there is a lot more friction from climbing waves and slamming into chop that slows the boat and moves the apparent wind aft.
This article will specifically explore non-hiking condition with three to six knots and minimum one foot chop.
Your body weight controls the speed of the boat and the amount of weather helm. Too little body weight on the rail and the boat will not go fast in the flats, or accelerate down the back of the waves. Too much body weight on the rail and the boat may lose weather helm between waves, resulting in a loss of feel and difficulty steering to the waves and optimal angle.
Optimal weather helm ranges from five to ten degrees of heel depending on wind strength and wave size. The lighter and choppier, the more weather helm the boat will need to navigate sets. That being said, the foils will lose grip if too little weight is on the rail during sets. The happy medium is a narrow range, which is why crew weight must be fully active during bad wave sets and accelerate (hiking) into the flats. Body movements also help propel the boat forward. In bigger wave sets it is useful to lean aft to help punch the nose through waves.
Good steering reduces the impact drag of your boat hitting each wave. It also reduces rudder drag of the boat wanting to head up beyond optimal upwind angle, which causes you to make a corrective steer. You should have a general idea of the best sailing angle in flatter spots by watching your telltales. When you hit the waves, that angle should be your highest angle of steering and you should never go above it.
Rather, steer down the backs of waves to produce power and weather helm then help the boat ride back up to your optimal angle as it crashes the next wave. Depending on the wave pattern, this could be a rhythm of pulling and pushing the tiller every 1 to 3 seconds.
Two of the easiest places to make mistakes when steering are:
- When steering too low and not coming back up to optimal angle by the time your boat crashes into the next wave, in turn stalling the sail.
- When crashing into the next wave and steering above your optimal angle, in turn pinching the sail. Both scenarios will create a devastating amount of sideslip.
It’s difficult to be completely scientific about sheeting, but the key element is keeping your angle of attack on the sail exactly the same. If the apparent wind moves aft as it does when your boat is slowed by waves, then your boom should drop to leeward to keep the flow around both sides of the sail consistent.
Your body weight controls the speed of the boat and the amount of weather helm.
If you keep the sail sheeted in tightly, you will see the leeward telltales rise and sail begin to lose a large percentage of power. Easing will also allow for steering by increasing the range below optimal angle (sometimes referred to as steering groove). As long as you are consistently hitting waves and not accelerating up to your top speed, it is recommended to leave your sheet eased until there is a noticeable speed increase. Essentially, there’s no need to fan or pump your sail on each wave.
Set your sail up to be forgiving. Maintain some twist in the leech to allow for optimal flow during periods of choppy water or unstable conditions. Once maximum speed is reached tighten the leech by reducing twist and making a flatter sail with less drag. In the Laser, keep the boom vang at block to block setting so that easing the main both straightens the mast adding a deeper entry angle as well as camber, and drops the boom to leeward to accommodate for apparent wind moving aft.
Let’s put it all together.
- Sailing fast in the flats your body weight is maximized for top speed, sheeted in to accommodate for the apparent wind being forward and not steering too much.
- Wave/chop set approaching: ease sail before the first wave, ease body weight if it’s really light and you might lose weather helm. Steer straight into the first wave, not going above your current angle. After cresting the wave, pull the tiller to windward so the bow drops down the back of the wave and then let the boat roll back up to optimal angle as you hit the next wave. Keep repeating with sail eased until you hit a flatter section.
- Quickly add weight to get rid of excess weather helm and accelerate the boat (weight is paramount to boat speed) then trim your sail to the new forward apparent wind angle.
A lot of races are sailed in this sloppy and sticky condition. Not only upwinds but also downwinds can be quite frustrating. Residual chop from winds throughout the night can wreak havoc on a race course, and without good preparation, one can easily feel lost. During clinics at ISA we do dry land training in the boat to simulate the sequence of “ease, hike, trim” and prepare you for a very worthwhile day of training.
Vaughn Harrison has worked with countless Olympians, youth and masters sailors. He coached at the 2016 Rio Olympic Games and founded ISA in 2008.
For more information – http://internationalsailingacademy.com/