BetaGPS, motion sensors and video on one clock

Sailing telemetry, decoded.

Spada Sailing reads the telemetry inside GoPro, Insta360 and DJI files and the logs of a Vakaros, Velocitek or watch, puts every boat on GPS time, and works out the wind, the heel, every manoeuvre and the race from it.

How it works

Runs in Chrome or Edge, nothing to install. Your videos stay on your computer.

Beta. Spada Sailing is best experienced on a PC or tablet. It is in beta and many features are coming.

Recorded in Spada Sailing: a training session from two GoPros and a 61-boat ILCA 6 race from its trackers. Sailors and boats are renamed, and no video is shown.
GoPro GPS
10–18Hz
read from the file, no export
Gyro + accelerometer
~200Hz
heel, pitch, sea state
Wind direction
3–4°
from the GPS alone, checked against boats’ compasses
Video uploaded
0bytes
it plays from your computer
Map playback
61boats
at 60 fps in the browser

The starting point

Where the time goes in a video debrief

Hours of footage

Each camera records a session as several large files. Finding the start, or one particular tack, means scrubbing through all of them.

Numbers elsewhere

Speed and tracks live in another app or logger, on its own clock, so the video and the data are looked at separately.

Syncing by hand

Comparing two sailors means lining up their videos by hand, on a sound or on something both cameras happen to see.

Spada Sailing does the syncing, the measuring and the searching, so the debrief time goes to the sailing.

Under the hood

From raw files to a debrief, step by step

Video is read where it lies and never leaves the computer. Only the sensor series go to the server, for the wind, the heel and the sea state.

  1. 01 · Parsein the browser

    Read the telemetry in the file

    The GPS and motion data a GoPro, Insta360 or DJI camera records inside its video files, read without playing them, and the logs of trackers and watches. Split recordings join into one clip.

    A 4 GB file in a second or two
  2. 02 · Syncin the browser

    Every clock onto GPS time

    A camera without GPS is lined up by how its gyroscope felt the boat turn against how the GPS course turned; a logger by its heel against the camera’s.

    Lined up to within a second, no offsets to set
  3. 03 · Attitudeserver

    Heel, pitch and the sea

    Heel and pitch from gravity and the gyroscope, on any mount fixed to the hull and with nothing to zero; the sea state from the heave between the waves.

    Heel · pitch · sea state
  4. 04 · Windserver

    The wind from how the boats sailed

    Direction from the tacking angles of every boat on the water, speed from each class’s polar, fitted on fleets’ racing data; a weather model and tide beside it.

    Direction · speed · how sure
  5. 05 · Analysein the browser

    Manoeuvres, legs and races

    Tacks and gybes, legs, VMG and metres gained along the wind; starts, lines, marks and finishes found from the fleet; a score per sailor against logged norms.

    Tacks · legs · VMG · races · scores

Compare sailors

See who gained, where, and why

One column per sailor, each measured against a reference sailor you choose.

  • Distance gained along the wind, tacks and gybes included
  • Upwind and downwind VMG, speed, wind angle and heel side by side
  • Over the same minutes of steady sailing, so a wait or a capsize doesn’t skew it
  • Where each sailor gained and lost most, and the fastest ten seconds
  • Leg by leg: average VMG and metres gained on every leg
  • Click any row to watch it in the video
Head to head: distance gained, VMG, speed, wind angle and heel for two sailors over the same minutes of upwind sailing
A whole session, two sailors, head to head.

Debrief

The debrief, written for you

Open a session and the debrief is ready: what each sailor did well, what cost them, and the video of each.

  • Strengths and what to work on, in metres gained or lost
  • Upwind, downwind, tacks and gybes: where the metres went
  • A highlight reel of the moments that mattered, to play or export as a video
  • A score for each part of the sailing, and each sailor’s progress over time
  • Copy it into a message, or share the report as a link
The debrief: one sailor’s strength, the other’s metres lost upwind, downwind and in tacks, what to work on, and a highlight reel of three moments
Strengths, what to work on, and a two-minute highlight reel.

Camera sync

Cameras without GPS, lined up by the boat’s motion

An Insta360, a DJI or a GoPro without GPS records on its own clock. Spada Sailing compares how its gyroscope felt the boat turn with how your GPS track turned, and finds how far apart the clocks are.

From then on the video has the track’s speed and position, and the track has the camera’s heel.

Against a GPS track
within about a second
Against a Vakaros’ heel
within a few tenths
GoPro with its own GPS
already on GPS time
Insta360 X4, on its own clock
Heel14°camera
Pitch2°camera
Speed–GPS
Course–GPS
Drag to look around
Vakaros track: how the boat turnedCamera gyroscope
Camera on its own clock
Track
Simulated: an Insta360 X4 on its own clock and a Vakaros track. Drag the picture to look around.

Wind, heel and tacks

What you get from a session

From the cameras and trackers you already have: nothing extra to fit, and nothing to calibrate before going out.

The wind, from the boats

Direction and strength worked out from how the boats sailed, drawn over the water as it shifted and gusted.

Heel, pitch and sea state

From the camera’s own motion sensors on any mount fixed to the hull, with nothing to zero.

Every tack, measured

The speed through each turn and the metres it cost, with a debrief and a score for each sailor.

Races

A race set up from the tracks, for a pair or a fleet of 60

The starts are found in the tracks; one click sets up the line, the marks and the finish, each for you to check. Practice races with a line or a rabbit start, or a regatta from its trackers.

Start and line

The gun from when the fleet took off, the line from where the boats were at it. Nudge the gun by seconds, drag the line’s ends, or let the rabbit’s tacks set the gate.

Marks and legs

A mark wherever the fleet turned, gates as pairs, in rounding order. The legs are built from them, with every boat’s split, place and gap at each mark.

Results

Early or late at the gun, distance from the line, speed and VMG off it, places through the race, finish times and a scorecard. Any leg opens in the analysis like any other part of the session.

GPS estimates for training, not official results.

How it works

From the boat to the debrief in four steps

  1. Record

    A camera fixed to each boat: a GoPro with GPS on, or any camera with a Vakaros, Velocitek or watch on the same boat.

  2. Add the files

    Drop the files or a whole SD card. Split recordings are joined into one clip, and even a 4 GB file opens in a second or two.

  3. Sync

    Every video is put on GPS time: a GoPro by its own GPS, other cameras by their motion against the track. No offsets to set.

  4. Debrief

    Compare sailors, tacks and metrics, and click anything to watch it in the video.

Who it’s for

Sailors, coaches and squads

Sailors

Go through your own session at home: where you lost on your training partner, which tacks cost most, and the video of each.

Coaches

Debrief a group from the cameras on the boats. Compare sailors on the same leg, score practice starts, and show the exact clip.

Clubs and federations

The same measurements across camps and sailors, with no instruments to buy or keep up beyond the cameras.

Supported files

What it works with

If a file isn’t supported, Spada Sailing says why when you add it.

Camera or deviceVideoGPSMotion sensors
GoPro HERO5 Black to HERO11 Black, HERO13 BlackYesBuilt in, on GPS timeYes
GoPro HERO12 Black, HERO11 Mini, HERO7 White, HERO (2024)YesAdd a GPS track: it lines up by itselfYes
Insta360 X3, X4, X5360°, look aroundGPS remote, or add a trackYes
DJI Osmo Action 4, 5 Pro, 6YesDJI GPS remote, or add a trackYes
DJI Osmo 360360°, look aroundDJI GPS remote, or add a trackYes
Phones, DJI Osmo Pocket, any .MP4, .MOV, .M4V, .WebM, .MKVYesNo: on the camera’s clock, lined up by handNo
Vakaros, Velocitek, Sailmon MAX, watches (.vkx, .vtk, .fit, .tcx, .gpx, .csv, .log, .nmea)NoYes, matched to the boat’s video by itselfHeel and trim from a Vakaros or logger

Not yet tried on a real boat’s file: DJI cameras with the GPS remote, the Osmo 360, and the Insta360 X3 and X5.

Not supported

  • GoPro MAX 360° files, Apple ProRes, .AVI, .MTS and .WMV. Save them as .MP4 first.
  • A map or speed for a camera without GPS, until you add a GPS track of the same boat.
  • Frame-exact sync from a GPS track alone (about a second; a GoPro with GPS needs none).
  • Wind speed from an instrument: it is estimated from how the boats sailed.
  • Live use on the water: it works from the files afterwards.
  • Safari and Firefox on a computer: use Chrome or Edge. Phones work too.

Your files

The videos stay on your computer and play from there. They are never uploaded.

Their GPS and motion data go to the Spada Sailing server, which works out the wind, heel and sea state.

Start with your last session

Open Spada Sailing and drop in the videos and GPS tracks: a folder, an SD card or a few files. Spada Sailing is in beta, and more is on the way: tell us what you miss with the feedback button in the app.

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