Sailing performance analysis software: instruments, GPS apps and what each can tell you

Sailing performance analysis software turns a recorded session into answers: how fast you sailed at each angle, how much each tack cost, and which leg was best. If your boat has calibrated wind instruments, software such as Expedition works from that data and is the stronger choice for polar targets. If you sail with a phone, a watch or a GPS unit such as a Vakaros Atlas, apps like Waterspeed, Vantage and ChartedSails analyse the GPS track.

Compared as of October 2026, from each product’s website or App Store listing and, for Waterspeed, its help centre. We make Waterspeed; corrections welcome at support@waterspeedapp.com.

What does sailing performance analysis software do?

It splits a session or race into legs, runs and manoeuvres you can compare. Typical outputs are speed, VMG, true wind angle, tack and gybe cost, a polar chart and a replay. Which numbers matter: Sailing performance metrics.

What is the difference between instrument data and GPS-only analysis?

Instruments measure the wind and the water on the boat; GPS only measures where the boat went over the ground. That decides how far the analysis can go.

A GPS track gives speed over ground (SOG) and course over ground. It does not measure the wind, so a GPS-only app takes the wind direction from a forecast or from you, or estimates it from the track. It cannot measure wind speed on the course, and with no speed through the water it cannot separate current from your own speed.

An instrument system adds a boat speed sensor and a masthead wind sensor, and calculates true wind speed and angle second by second. Polar targets need exactly that: the target speed for this wind speed at this angle. On wind shifts, current and target speed, instrument-based tools are clearly stronger, provided the sensors are calibrated.

GPS-only analysis still answers a lot: manoeuvre losses, speed consistency, leg comparison and your best angle on a steady day. It needs no extra hardware and works on boats with no instruments. See How accurate is GPS on the water?.

How do the main tools compare?

They differ most in where the data comes from and how they handle the wind.

Tool	Data source	Wind	VMG	Polars	Manoeuvres	Replay and comparison	Platforms
Waterspeed	Phone and watch GPS; Garmin, COROS, Suunto sync; Vakaros VKX, GPX and FIT import	One average direction per session, from the forecast or set by you	Yes, by leg (Ultra)	Your own polar from the track (Ultra)	Tacks and gybes with entry and exit speed	Replay; compare two sessions	iPhone, Apple Watch, Android, Wear OS, web
Vantage	Records in the app; Sailmon, Vakaros and Garmin devices	Detects minor wind shifts during the session	Yes	Not listed	Manoeuvres	Replay with video; share with peers and coaches	iPhone, iPad, Mac
ChartedSails	GPS tracks from its app and from devices such as Vakaros, Garmin and Velocitek	Shows true wind angle and wind direction	Yes	Not listed	Manoeuvres, including tacks	Replay synced with onboard video; compare with other boats	Web, iOS, Android
Sailmon app	Sailmon devices	Not listed	Not listed	Targets you fine-tune; polars not listed	Not listed	Replay with per-second speed, heel, pitch and COG; compare with partners	iPhone, iPad
Expedition	Instrument systems via NMEA 0183 and NMEA 2000	From the instruments	Not listed	Output, analyse, create and modify polars	Not listed	Replay and analyse logged race data; track competitors	Windows

“Not listed” means the feature is not on the product’s website or store listing.

Waterspeed

Waterspeed analyses the GPS track from your phone or watch, or from imported files. It shows every tack and gybe with entry and exit speed, your best speeds and a replay with the speed chart. Ultra adds VMG by leg, upwind and downwind legs, port and starboard runs, and a polar chart from your own track. Vakaros files come in as VKX: see the Vakaros + Waterspeed workflow.

The limits are those of GPS: one average wind direction per session, no shifts, and a polar of your boat as you sailed it that day, not a class polar.

Vantage

Vantage is an app for competitive sailors. It takes data from Sailmon, Vakaros and Garmin devices, or records in the app, and analyses speed and manoeuvres automatically. Its listing says it detects minor wind shifts for its VMG figures, and you can share data with peers and coaches.

ChartedSails

ChartedSails turns a GPS track into races, legs, manoeuvres and straight lines. It shows SOG, true wind angle and VMG, syncs onboard video to the replay, and compares you with other boats. Groups and PDF reports suit teams.

Sailmon

The Sailmon app uploads trips from Sailmon devices and replays them on a map with per-second graphs of speed, heel, pitch and course. You can compare with partners who sailed at the same time and place.

Expedition

Expedition is Windows navigation software that connects to instrument systems. It logs race data to replay or analyse later and can output, analyse, create and modify polars. It is the instrument-based option here.

Where does the Vakaros Atlas fit?

The Atlas records data; it is not analysis software. Vakaros says it logs sensor data at up to 10 times a second and exports VKX and CSV files for tools such as SailNjord and ChartedSails. Waterspeed imports VKX too.

How do you choose sailing performance analysis software?

1. Start from your data. Calibrated wind instruments point to an instrument-based tool; a phone, watch or GPS unit to a GPS app.
2. Decide what you need to learn. Manoeuvre cost and leg comparison work from GPS. Targets against true wind need instruments.
3. Check how the wind is handled. A fixed direction is fine on steady days and can mislead on shifty ones.
4. Check your devices. The tool must read the files your watch, phone or instrument produces.
5. Think about the team. Coaches and fleets benefit from shared data, video and boat-on-boat comparison.
6. Keep the review short: a ten-minute routine you repeat. See How to analyse a sailing session.

Related: What is VMG?, Upwind angles and VMG in a dinghy, Polar charts, VMG and true wind angle, Tacks and gybes analysis.