SailTimer app

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Using Live Wind Data in the App

Convert between Apparent and True wind speed and direction:  If you have real-time wind data coming in to the app from the wireless SailTimer Wind Instrument™ or Onboard Network in Setup, when you click on the speedometer to show a large view, you'll see a button in the top right that allows you to convert between true and apparent wind speed and direction.  Whichever way you leave it is displayed on the Wind Speedometer is what will be displayed with the grey wind arrow that moves around the boat (when the speedometer icon is small), and in the Input\Wind panel.  However, the app always uses True wind for the polar learning, optimal tacks and Tacking Time to Destination. 


Display the port or starboard tack first, with a new < > button at the bottom left of the charts screen (see screenshot below).  Very handy for avoiding obstructions.  If your optimal tacks are symmetric, you can also let the app automatically display the tack that is closest to your current heading.

Share graphs of wind and boat speed
for up to the last 24 hours of sailing.  As you can see from the graph below, it now includes 3 lines, for the boat speed (orange), Apparent wind speed (blue) and True wind speed (green).  This is an interesting record of your sailing for the day.  In the example below, you can see the yellow boat icon on the background.  The boat had just turned downwind. Therefore, you see the Apparent wind speed dropping on the right end of the graph until it has the same speed as the boat (and onboard, it feels like the wind has just stopped).  However, the True wind speed (green line) is unaffected, and is now higher than the blue line for the Apparent wind.  So the app is accounting for the boat speed and direction, to calculate the True wind speed.  When going upwind, the apparent wind rises and the blue line is above the green line.


How to share a screenshot or just the graph.  The screenshot above is taken on an iPad/iPhone by pressing the On/Off button and the round Home button for a second at the same time (you'll hear a snapshot sound). Then go to the Photos app where you'll find the screenshot, which you can email.  This approach is nice because it shows both your GPS track, the map of your location, and your boat and wind speeds for the day.  Pretty cool.  However, if you don't want the background, you can quickly email the graph alone from within the Sailtimer app, as in the example below. The graph below was made at the same time as the screenshot above, so you'll notice that the lines are the same.  To get the graph without the background, just press the Email button in the top right corner, and email it to yourself or share it with others.



Polar learning:  Generate custom polar plots for your unique sailboat.  Polar plots or tables show your boat speed in all wind directions and wind speeds.  Until now, it has been difficult to get polar plots from a velocity prediction simulation or manufacturer;  they don't exist for many models of boats, and are expensive to purchase at sources such as this one.  But as shown in the screenshot below, with a low-cost in-app purchase, the SailTimer app (and Charts Edition) can now easily learn the custom polars for your individual sailboat.  This is a major advancement in sailing technology.  Once the app knows the speed profile for your individual boat on all points of sail, it can give more accurate tacking results.  This actual data for your individual boat is far more accurate than generic polar "targets" for all boats of the same model.  They assume that every boat of the same model has the same speed profile (whether clean for racing, or full of cruising gear), and are based on estimates rather than empirical data.

You can see where it says that new polar data was saved, in the bottom of the panel on the above screenshot.  There are also times when no learning should occur, such as when you are motoring straight into the wind, tied up at the dock, swinging at anchor, and for example when you are tacking.  The app therefore follows our Rules for Intelligent Polar Learning...  If the conditions are not stable (e.g. you are changing headings while tacking) or you are heading straight into the wind or nearly stopped, then you will see a note at the bottom of the panel giving you feedback that polar data is not currently being saved.

Save multiple polars.  If you want to save different polars for different sail combinations, or for testing, racing or different conditions, this is another advanced feature that SailTimer makes really easy.  In the panel below, you can see that you can toggle the polar learning on or off.  You can also can save (or delete) lots of different polars, and select the one you want to use.  You could save polars for sailing with main and jib, and a different polar for using main and genoa.  That way, when you want your optimal tacks and Tacking Time to Destination, if you select the polar for the sails you are using, you will get the most accurate tacking results.  That's another innovative new feature that is available in the SailTimer app, but not in any GPS chartplotter. 



Page 1:  How to Use the SailTimer App

Page 3:  Live Overlay of Wind & Race Maps - Crowdsourcing


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