Avelsta Guide Online NKE reader Open Avelsta

Getting started

What is Avelsta?

BeginnerUpdated

Avelsta analyses your NKE sailing logs: sessions split automatically, replay on the map, statistics, polar percentage and boat speed polars generated from your own data.

The essentials

Avelsta is a web app for sailing performance analysis. You upload the logs recorded on board by your NKE instruments; Avelsta splits them into sessions, shows them on a map with speed, wind and angle curves, and constantly compares the boat speed with its speed polar.

  1. Upload your log files (.LOG from the NKE Box WiFi, .nkz from the NKE Processor HR).
  2. Avelsta rebuilds your boat’s timeline and splits it into sailing sessions.
  3. Open a session: track on the map, timeline, replay, statistics and polar percentage.
  4. Generate your boat’s real polar from your sessions, or import an existing polar.
The Avelsta home screen: latest sessions, primary polar and activity
The home screen of a signed-in account

Avelsta runs in the browser, on a computer or a tablet. Nothing to install.

Going further

Who is Avelsta for?

Racing sailors, offshore sailors and cruisers curious about their performance: anyone who records their sailing data and wants to know what percentage of its potential the boat sailed at, in which conditions and with which sails.

What you can do

Need Where to find it
Replay a sailing session, second by second Analyse a session
Understand TWS, TWA, VMG or polar % Timeline measures
Get your boat’s real polar Generate a polar from your sessions
Compare your speed with a reference polar Polar percentage (POL)
Know which sails to carry in which wind The sailmap
Isolate a leg, a manoeuvre, a trim setting Segments, checkpoints and notes

With or without an account

You can try Avelsta without an account: your logs are analysed and deleted after 6 hours. With a free account, your boats, sessions and polars are kept and visible to you only.

The data used

Avelsta reads what your instruments recorded: GPS position, speed over ground (SOG) and through water (STW), heading, apparent and true wind, heel, pitch, current, depth… It never changes your files: the raw file is kept as is and can be downloaded from each session. Details: Supported log formats.

Frequently asked questions

Is Avelsta free?

Yes. The trial without an account and the account are free. Without an account, each upload is limited to 200 MB and the trial is deleted after 6 hours.

Which instruments are supported?

NKE files: .nkz from the NKE Processor HR and .LOG (NMEA 0183) from the NKE Box USB Datalog WiFi datalogger. See the online NKE file reader. Other formats are planned.

Do I need to install an app?

No. Avelsta runs in a recent browser at avelsta.app.

See also

  • Try Avelsta without an accountUpload your NKE logs without creating an account: replay and generated polar in a few minutes. Trial duration (6 hours), limits, and how to keep your sessions by creating an account.
  • Explore the example sessionDiscover Avelsta without your own logs with a real 23-hour example session, read-only, compared with its boat’s polar.
  • Import your sailing logsImport NKE logs (.LOG, .nkz) into Avelsta step by step: choose the boat, drop several files, upload, background processing and end-of-import notification.
  • What is a boat speed polar?A sailboat’s speed polar gives the target speed for each true wind angle and true wind speed (TWA, TWS). Reading the diagram and the table, theoretical polar and measured polar.