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Optima, speed polars of a sailboat

The indispensable tool for creating polars actual sailboat.

Show laylines, know the target speed of the boat and the angle that achieves the VMG or calculate a route, it is all possible thanks to Adrena essential navigation polars.

So how do you create and use a polar in Adrena? Several options are available to users…


Calculate the polar

Optima, the calculation tool integrated into Adrena software, uses data recorded automatically during navigation to establish the polar curves of the boat. Rare feature among navigation software, this powerful tool provides excellent accuracy for the display and use of the actual performance of the boat. The calculation process is divided into three steps:

  • the load of the tracks used for the calculation. It may be all the recorded data or only a portion (eg only regatta tracks)
  • the calculation of the curves by the software and any manual corrections
  • the registration of the polar file newly calculated.

We can thus create different files to have a polar « crew » or « cruising solo » or even depending on the sea state (dedicated buttons are provided for this).

Calculation of polars

 

 

Activate a polar

Once the boat’s polar file is created, the crew can immediately use its data contained by activating the polar in Adrena software. In the menu « Tools> Activation polar » software provides the ability to activate a different polar for the start phases and phases of navigation. If you do not have a specific polar for each phase, then the same file is activated in both case.

 

Theoretical polar and VPP, use them as reference!

In some cases, there is only theoretical polar – or VPP – recovered from the manufacturer or the architect who designed the boat. It is a good base to start racing and get performance values around the potential of the boat. These polars can be activated to be used immediately.
When there is not enough tracks recorded to cover all ranges of use of the boat, it will be useful to complete the « holes » left by the lack of data in certain circumstances.
Thus the active polar initially based on theoretical data of the polar reference will be refined over the navigation by the speed recordings.

Menu Optima






In Optima menu it is possible to define a reference polar, it is not the software active polar. It is used in the window “calculation of polars”, by ticking the box “replace missing data with reference polars” to complete the calculation.









  

Polar

 

              Theoretical polar                                     Missing data inserted                          Final calculated polar
 

Difference between theoretical and calculated polar

Difference between theoretical and calculated polar

 

  Theoretical polar                                        Calculated polar


What if I do not have any theoretical polar ?

When the theoretical polars are missing, last solution is based on mariner’s experience and knowledge of his boat : it is to write its own polar. From an Excel pivot table, you define the boat’s target speeds according to the wind angles and the wind speed.


The table should be as following:

TWA/TWS

4

6

8

10

——

——

——

40

 

 

 

 

 

 

 

45

 

 

 

 

 

 

 

60

 

 

 

 

 

 

 

75

 

 

 

 

 

 

 

——

 

 

 

 

 

 

 

——

 

 

 

 

 

 

 

——

 

 

 

 

 

 

 

The table should star tat first line, fisrt column of the first sheet of your excel file.

Save your file in text format (tab delimited) (.txt)

Retrieve in Windows explorer the file and select it. Modify the extension from « .txt » en « .pol »

Then, you can activate the polar in Adrena.

The description of how to use those tools can be found in the user manual delivered on every ADRENA software CD or in our website in the FAQ.

 

How Adrena is using the polars?

Layline display on departure line



Laylines display on departure line 




Layline display



 




Layline display and VMG heading to waypoints

 

 

 

 

 

 

 

 

Performance data display

 

Performance data display 

 

 

 

Target duration display

 

 

 

 

 

Target duration display

 

 

 

 

 

 

 

Weather routing calculation

 

 

 

Weather routing calculation