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VMG, velocity made good, is the number that explains why the faster boat does not always reach the mark first. This guide covers what VMG actually measures, the pointing versus footing trade-off, reading polars, why sailing extra distance downwind wins races, the live-VMG trap, and how to measure all of it from a plain GPS track without instruments.

Most sailors now carry a GPS logger without thinking about it, but the tools for turning that data into something useful vary enormously depending on what kind of sailing you actually do. This post compares the main sailing analytics platforms available today, including SailingMetrics, RaceQs, TackTracker, Kwindoo, eStela, Expedition, Sailmon, Velocitek, the Vakaros Atlas, and the professional systems behind America's Cup coverage, and works through which one actually fits club racing, dinghy training, offshore passages, or event organisation.

SailingMetrics now supports Vakaros VKX files, the native telemetry format of the Atlas 2 and Atlas Edge. If you have been uploading GPX exports from the Vakaros app, switching to VKX gives you the full 10 Hz sample rate, heel and heading data from the onboard IMU, and start line geometry from your pre-race pings. This post explains what is in a VKX file, how to export it, and what you will find in your analysis once it is uploaded.

Sailing races are mostly invisible to the people who care about the sailors in them. The action happens a kilometre offshore and all you can do is wait. SailingMetrics live tracking changes that: with a single shared link and no app required, family members and spectators ashore can follow every boat on the water in real time, see who is leading, and get notified the moment a specific sail number crosses the finish line.

Accurate wind data is the foundation of fast sailing and until now, SailingMetrics users had to estimate it by hand. Version 1.0.84 changes that with native Bluetooth support for the Calypso Ultrasonic Wind Meter. Live wind speed and direction now stream directly from the sensor to your phone, attach to every GPS fix in your recording, and feed automatically into VMG, tacking analysis, and league race scoring. No wiring, no proprietary displays, just clip it to the shroud and go.

We have just launched a new analysis feature that uses artificial intelligence and computer vision to track how your body moves through every tack in your session. For the first time, SailingMetrics can show you the data behind your tacking technique, so you can see what your coach sees from the shore and start making real, measurable improvements.

Compare GPS tracks from multiple sailors on the same map, automatically segment each track into upwind, reach, and downwind legs using gate lines and marks, and analyse duration, distance, average speed, and VMC side by side. SailingMetrics Course Analysis gives coaches and sailors a data-driven debrief that goes beyond reviewing a single track at a time.

Recording a GPS track during a sailing session is easy. Almost every sailor with a smartphone does it. But most of that data never gets properly looked at, and when it does, it often gets reduced to a colourful line on a map and a top speed number. The real value is buried a little deeper, and once you know where to look, a single session's GPS file can tell you more about your sailing than a month of vague feedback from the shore.

Teaser: iSail was one of the first apps to bring GPS race analysis to club sailors, letting you replay your track and compare it against your competitors after the race. It quietly disappeared around 2017 and the website is now a parked domain. If you've been looking for a replacement, the good news is that the tools available today are considerably more capable. This post covers the best iSail alternatives, with a focus on what actually helps you get faster.

Post-processing a GPS track can tell you a lot about what went wrong in a training session. What it can't do is help you fix it in the moment. In a dinghy, the feedback loop between what you do and what the boat does is measured in fractions of a second. That's exactly where live metrics come in. Here's why real-time data and post-session review are better together than either is on its own.