Shift season? No, pressure season
In modern sailing we encounter various classes of boats with different characteristics.
The evolution of skiffs and foils have generated the necessity for the evolution of the skills of pressure hunting.
In slow boats sailing upwind there rarely is an advantage to sailing in pressure rather than shifts as the boats ability to accelerate in a worthwhile manner is very limited.
In most conditions classes such as optimist and even a laser will have a far greater benefits of sailing lifts to ensure the best average VMG for them.
More modern and advanced classes posses a much greater ability of accelerating rapidly even at a very small increase of wind speed, in many cases this acceleration may be worth their VMG more than a big wind shift, hence those classes are more dependent on pressure rather than angle to ensure the best average VMG.
Downwind as mentioned in the previous blog sailing in pressure generates greater speed and will allow the boat to sail at a lower angle and require less distance towards the bottom mark.
So what is pressure?
Pressure or a gust is an air turbulence created at the boundary layer that reaches the surface of the water, or generated by a temperature difference on the surface, either by a current mixing the water or a cooling/heating of surface due to shade or coloring.
A cooler surface will be dumping pressure towards a warmer surface. The main point is that the pressure patch (seen as darker coloured water), will be stronger wind than that around it.
Pressure has a tendency of moving at different speeds, in some conditions pressure will be moving faster than other conditions, we may even encounter conditions in which there are multiple drivers for the wind so every gust may behave differently and move in a different speed. By this we mean that the dark patches on the water may move fast or slowly going downwind. Anticipating their path and longevity is a skill in itself.
The importance of the pressure speed of movement is crucial for a successful race plan as it will determine our course of action once hitting the pressure.
For example if the pressure from the left is faster moving than the one coming of the right we would prefer to consolidate using the pressure off the right as we will increase the likelihood of sailing longer periods within that pressure.
Our ability to judge the wind speed within the gust is another important skill as we will probably want to choose the stronger gusts when possible.
How do we spot that pressure?
The most common way to spot pressure is by observations of the water surface, the wind blowing on the surface of the water creates small ripples on the water, the stronger that gust is the darker the water will appear, this also allows us to keep track of the gusts speed of movement and direction.
Another way of observation is by looking at other boats, yes it is a lot harder to be able to tell by the position of the crew or the heeling of boats in the distance but experienced sailors should be able to tell whether a group of boats in the distance is sailing in a gust or in a lull and judge whether they will be able to make use of that knowledge or not.
During our training sessions at Toplevel Sailing we ensure to develop the skills necessary to be able to spot and prioritize the use of pressure for their advantage.
Want to learn how to hunt pressure? Join our training camps