Layline

About Layline

The App uses the GPS data available internally from your device, in addition to (the extent available) data from the yacht wind, water speed and compass instruments, that is transmitted to the device using a WiFi bridge, with UDP network protocol and NMEA 0183 data protocol, to calculate tactical racing information.

The App is designed to present processed information / answers to the User that can be understood and used immediately, rather than data sets or complicated graphics that require the User to divert their attention off sailing the boat to obtain conclusions.

The following functionality is provided by the App (to the extent possible from the data streams connected to the device). The items marked with * are only displayed following an in App subscription purchase.
(Note however that the initial Release Version 1.0 has all the Pro features enabled free until 30 July 2024.)

STARTING
- High quality starting timer with +/- minute adjustment and synchro to closest minute.
- Local time displayed to assist with starting timer.
* Crossing point on start line for starboard close hauled course.
- Speed bar to judge appropriate time to burn indicator to use.
* Time to burn presented for 3 cases of approach to start line;
i. At 100% close hauled polar speed
ii. At 70% close hauled polar speed
iii. At actual speed of approach to line.
- Automatically adjusts for upwind or downwind start.
* identifies the advantaged end of the start line.

RACING
- Displays current and next mark of Course.
* Displays relative wind angle for next leg (useful for identifying which side the spinnaker needs to be set, and whether the wind angle is suitable for using a spinnaker)
- Auto advances through legs of the Course but can also be advanced or backed up manually by swipping down/up.
* Displays comparator for advantaged tack / gybe relative to 6 minute moving average of ground wind direction.
* Displays comparator for course direction relative to upwind optimum polar (for beating upwind), course to mark (for reaching) or downwind optimum polar (for downwind gybing).
* Displays comparator for % target speed (determined from polar data).
* Displays distance and time to layline (upwind or downwind). For gates, or finish line, this is displayed for both marks and the closer mark to sail is identified.
* Displays current in direction of travel. For upwind tacking this can be selected to be used to correct distance and time to layline.
* Displays crosstrack for your heading relative to the current mark.
* Displays relative direction to current mark (relative to heading).
* Displays distance to current mark.
- All bearings and distances are calculated on a Great Circle initial bearing basis (rather than rhumb line).

COURSE AND START LINE
- Course selected from drop down list
- User is able to enter Wind Direction and Wind Speed manually if only device GPS data is available.
- User tags location of pin and start boat for start line. Line length trim is available for the start boat end of line.
- For windward / leeward courses, the User can enter the distance and bearing from the start boat to the windward mark (and wing mark if applicable). The User can select Auto Reposition for these marks whereby the App automatically updates the actual position of the mark when the yacht is detected to have rounded the mark.
- Graphical display of Course.

RAW DATA DISPLAY
- Screen displays all the input data acquired by the App.
- A calibration tool is provided for determining a calibration adjustment for the speed through water transducer.

REPLAY
- Race data is able to be logged, exported and Replayed by App. Full App functionality is displayed in Replay mode (this can be used to test satisfaction with the full App before purchasing a subscription).

A full User manual, together with other resource material, is available in the folder:
https://drive.google.com/drive/folders/1VdEuO2tNSlgu4v5yg-7awCcLC6G2wFc5?usp=drive_link