#SHIFTY MEANS HOW TO#

If possible, the route should be redone during the race to factor in actual present position and changes in forecast.įor the smaller scale, prediction is less important than knowing the current conditions and how local knowledge will affect them. If your race is on a scale commensurate with the GRIB, you should certainly consider doing an optimal route to set strategy. GRIB files generally predict wind every 3 hours on a grid 30 miles on a side. For many sailors, Expedition is the optimal router of choice. This technique uses weather prediction (in the form of GRIB files) and polar curves to determine the fastest path to the finish line (here is a free GRIB file viewer). Optimal routing is commonly used on long distance races. We’re interested in shifts with a time scale from say 10 seconds to the length of the race (hours to days). Shifts on a time scale much longer than the race are also only of academic interest. By definition, wind shifts of less than the reaction time of the boat can be ignored. Wind shifts occur at all time scales – from seconds to days. Another important but less understood phenomenon – wind shear – is discussed here.

#SHIFTY MEANS HOW TO#

On this page, we’ll discuss wind shifts and how to extract maximum performance from them. This is not news to sailors, who are constantly dealing with shifting wind and wave to maximize performance. Wind shifts are annoying but they provide more opportunity for gain than anything else.

Shifty means