These are the polar performance diagrams for the four boats tested in 2018 with an upwash correction applied to the filtered data.

The codes after the boat name in the title indicate what filtering and corrections have been applied.

S7 means any data points where the wind speed drops by more than 0.7 knots per second are omitted.

A64 means that any data points where the wind direction changes by more than +6 degrees or -4 degrees per second are omitted.

Where points are filtered out, all subsequent data points are also filtered out until the boat speed changes. This is because the boat speed data feed changed less frequently than the wind data feed, and because in reality, the boat speed changes more slowly than the wind.

Avg3 means that the speed shown is the average of the top three boat speed values recorded for each wind direction and wind speed

C70D10 means a correction has been made on these results for downwash affecting the wind sensor, which was placed on the quarter of each boat. Results have an arbitrary 10 degree correction at 35 degrees, tapering off to 0 and 70 degrees. 

No adjustment has been made for the length and sail area/displacement ratios. These will be added at a later date. 

No smoothing has been applied to these curves apart from taking the average of the three highest boat speeds for each wind angle and speed. The big dips and the gaps in the curves are caused by the limitations of the data recorded and by filtering. We may apply some smoothing at a later data to bridge the gaps and dips.


       " ...there is nothing - absolutely nothing - half so much worth doing as simply messing about in junk-rigged boats" 
                                                               - the Chinese Water Rat

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