Manual SailingPD

The manual contains all information for the use of Sailing Performance Dashboard.

A download of the software will also contain the full manual, most recent version.

Manual only:

A short introduction follows here.

Remarks: please e-mail to sailingpd (you know the sign)

Sailing Performance Dashboard

Sailing Performance Dashboard (from here on: SPD) is a program that receives and processes NMEA-183 records, including converted N2K- STNG- and ST-records from a multiplexer or other multiplexing device or application.

Many, sometimes complex, calculations are done and the resulting information is available in a number of ways: home-made NMEA records for your instruments, on PC-screen, via wifi over UDP and as sound: spoken advice!

SPD is available for:

- Windows 10 (only)

- Linux on Intel/AMD 64-bit machines (amd64 / x86_64)

- Linux on Raspberry Pi with 32-bits ARM (ARMv7 / armhf)

- Linux on Raspberry Pi with 64-bits ARM (AArch64 / arm64)


SPD uses at a minimum an RMC-record (from a GPS, for SOG and COG) and one of 2 kinds of wind-records (MWV-R or VWR). Records with True wind (MWV-T and the obsolete VWT) are ignored, as SailingPD itself calculates True Wind from Apparent in two different ways.

Additional other record types make it possible to produce a lot of extra information. NMEA records processed as input in this version are:


If VHW records are present (with speed thru water, STW) these can be used to calculate True wind instead of using SOG for True Wind (TWA and TWS).

Next to these NMEA-inputs, some information about the boat is needed.

- A polar, with target boat speeds for a range of true wind speeds at 10 m high and a range of true wind angles. To calculate actual performance against the polar, it helps to have a reasonably accurate polar. You can have an unlimited number of polars: Full Crew, solo, DH, Genua or HA, no-Spi, Big Waves, whatever. Polars are created by saving an Excel spreadsheet as a .CSV file. You can import a polar from jieter-ORC with a few clicks.

- A polar with heel degrees for a range of wind speeds and wind angles. This polar is available in the Speed Guide that can be purchased with an ORC certificate (at . A default heel polar is available in SPD. Also an Excel CSV, this heel polar.

- A deviation table for the electronic compass on board that produces the Heading info (HDx-records and more modern types). This deviation table can have any number of entries between 0 and 360 degrees. Steps of 15, 22.5 or 45 degrees are often used. A table with just zero’s will also work, but some outputs will then not be as useful as possible, like current detection. The deviation table can, from V1.9.8, also have separate rows for heel (SB and PT, 4 rows per bow). Again, Excel CSV.

- A correction table for the log (water speed) on board. These devices happen to have a varying error, dependent on speed and on bow (SB or BB sailing). Heel can also influence the error. This correction table has separate correction values for SB and BB, and can have any number of speed entries. Steps of 0.5 kts (between 0.0 to 10.0 kts or so) are probably a good start. Here also, zero’s will work but not help. No surprise: Excel CSV. In the boatspecifics file there is a Y/N option to select a correction table with heel (separate for SB and PT) included or one without heel. Heel values of 0, 10, 25 and 40 degrees are used. Of course, interpolation is applied to find the correction for the actual heel value.

The polar (boat speeds) is really needed; the other 3 (heel, deviation, log speed correction) can be used in a default form. However, the more correct information is provided, the better the results of Sailing Performance Dashboard are.

Using only SOG (from RMC) and wind (apparent speed and angle, from MWV or VWR) SPD can look up the target speed in the polar and then calculate the actual performance. Alternatively, STW from a VHW can provide speed for this calculation.

N.B: SOG and COG from a VDO message (AIS transponder) are not used; the update frequency (30 seconds or more) is not acceptable for the purpose of Sailing PD: show accurate performance data every second is impossible then.

Sources of NMEA records.

SPD can process NMEA records from 2 sources, for 2 different purposes:

- Replay Mode: from a file with raw NMEA records, logged earlier during a trip. It can be very useful to post-process a log, as SPD will calculate and show all kinds of interesting information from the raw data. More about this later. SPD is fast in Replay: 25.000 NMEA records/second on a simple notebook.


- Live Mode: from a live NMEA source with the right combination of records. In most cases, that will be a multiplexer of some kind (as you need GPS-records and wind instrument-records), or another piece of software that can relay NMEA records, such as OpenCPN and Signal K.

Of course it is also possible to use a software program like NavMonPC,VSPE or Franson GPSgate as an intermediary. SPD normally reads records from a single COM port and writes to the same port, a real one (via USB or old fashioned COM) or a virtual one as presented by Navmon or Franson. Flow control (via RTS-CTS) is available if needed.

There is an option to use a second COM port for the output of SPD instead of the port used to read from. Using this second port, you could route the output (home-made NMEA messages!) directly to an instrument display, bypassing the multiplexer.

Input over a TCP or UDP network connection is also possible.

Output from SPD.

The main output is on screen. SPD shows the results of all measurements and calculations on screen.

The second output is the log file.

Every time a combination of an RMC record (with SOG) and a wind record is made, calculations are done and a log record is written in a CSV file that can easily be read by Excel.

In a log file, 48 different values are recorded about every second.

You can automatically create a Deviation table, an STW correction table and some other useful info from the logfile.

The third output: home-made NMEA records.

SPD can send NMEA records filled with data from the program to your instruments. In this version, 18 different types of records can be used for sending messages to your instruments or navigation app.

The fourth output:

Information over wifi. Some of the most important stuff is broadcast over wifi, by the PC where SPD is running. It sends UDP messages to a UDP-listener, defined by IP address and port number. Can be a broadcast also.

The fifth output:

The program can write all of the NMEA records produced and sent also to a .TXT file. In that way, you can see what records your program has produced. May be useful for later analyses, next to the (more complete) log file. Also handy for debugging while you try to get SPD to do what you want!

The sixth output:

A copy of incoming NMEA records can be written to a .TXT file. This feature can be used just to log incoming NMEA when live records are used, or to create a selection of the NMEA records during a Replay of another log file. To shrink this file a bit, all those irritating AIS records are skipped.

The seventh output:

Voice! SPD can tell you (in a clear gender-age-neutral voice) what the actual performance is. The frequency can be set by a parameter in the boatspecifics file.

The eighth output:

SailingPD is able to send all available data over a websocket to listening browsers or other apps. Signal K is an obvious target. A Node Red JSON solution is available for this. You can provide also your own html files to display what you like to see in a browser.


SPD comes with a number of post-processors. They read an SPD log file, and can create STW-correction- and Deviation tables, with or without heel. Also, they will check boat performance for each TWS and TWA, check the windset alignment and check the boat's symmetry (rudder, heel, performance). And much more....


SPD can read an ORC-polar from the jieter polars database.

Just enter a sail number and create an SPD polar!