On the course

If the wind speed and direction would not change – it would not matter what course you take and when you tack when reaching the mark. Geometry is simple.

Navigating to a mark


Mark is displayed on the compass rose relative to boat heading.

Red color means that this is port rounding mark, green – starboard, yellow – gates.

Following parameters might be used navigating the mark:

  • Bearing
  • Turn instruction
  • Distance (and time) to mark
  • Course deviation
  • Cross track error

The mark after is displayed as a smaller gray circle.


laylines layline eta

If the polar is configured, laylines are calculated automatically from a polar data as the most efficient angle to the wind. If polar is not selected, laylines are calculated from a tack/jibe angle.

Time to layline (and a distance to layline) might be selected as an additional parameter. It is calculated using 6 minutes average values of boat speed, boat heading, wind speed and wind direction.



SailRacer keeps track of the heading, calculates average and indicates a shift on a main compass rose.

The middle line between red and green bars is the 6 minutes average heading. The width/size of red and green bars indicates the maximum shift during 6 last minutes.

Numeric heading value and a graph might be selected as an additional parameter.

Wind oscillation and development

windavg2 windgraph2

If you have on-board NMEA to WiFi transmitter, it is possible to configure app to receive wind data automatically.

SailRacer keeps track of the wind direction and speed changes, calculates averages and displays a wind shift on a main compass rose, and in 6 minutes and 1 hour graphs.

Depending on your position in a course, graphs are colored in red and green colors. If the wind direction curve in waving on a red area – port tack is more efficient, green – starboard.

Thin curve represents the wind speed.

Following parameters are available to monitor the wind:

  • Aparent wind
  • True wind
  • Wind average (6 minutes graph)
  • 1h Wind average (1 hour graph)

Polar efficiency


If the polar is configured, the efficiency parameter is displayed on the main compass rose. Efficiency % = ( Actual speed / Target speed from polar ) x 100.



If SaiRacer indicates the current (from COG/SOG difference from compass heading and water speed) it displays affected by current laylines (dashed lines) .

In the example above there is a current from the west, boat sails on port tack down wind. Jibe to a starboard tack should be done when mark crosses the dashed line and current will help to make a mark.

Current (speed and direction) might be selected to display as an additional parameter.