What is Orca GPX?
Orca GPX is a browser-based sailing GPX viewer and route animator. Import one or more GPX tracks from your navigation app or chartplotter, combine them into a multi-day voyage, replay the route on a nautical chart and export the journey as an image or video. GPX files are processed locally in your browser and are not uploaded to a server.
Orca GPX reads standard GPX tracks with timestamps, as exported by common navigation apps, chartplotters and tracking apps.
Features
Combine multiple sailing days
Each GPX file is one leg. Several legs are sorted by time and joined into one voyage. Orca GPX detects stops in harbour or at anchor automatically and condenses them in playback.
Replay your voyage
The boat follows the recorded track on the nautical chart (OpenStreetMap with OpenSeaMap seamarks). You control speed, timeline and map view; the map can follow the boat.
Built for sailors
Distance in nautical miles, speed in knots. SOG and COG are calculated from GPS positions, plus ship time, sunrise and sunset with day/night shading, a speed-coloured track, a symbol for sailing boat, catamaran, trimaran or motorboat (the trimaran folds its floats around the harbour) and named harbour stops.
Export your journey
A keepsake image as high-resolution PNG (up to 4000 px) with chart, track, harbours and summary. The track alone as SVG or PNG with transparent background. Or the whole voyage as a video (WebM, 720p or 1080p).
Private by design
No account, no upload: GPX files stay on your device. They are read in your browser only and stored locally there.
How it works
- Export GPX tracks from your navigation app or chartplotter.
- Drop one or more GPX files into Orca GPX, or choose them.
- Combine the legs into one voyage and give it a name.
- Replay the voyage on the nautical chart.
- Export the voyage as an image or video.
Your GPX files stay with you
Orca GPX has no backend, no login and no database. Your GPX files stay on your device: they are read in your browser only and stored locally there so your voyage is still here after a reload. They are not uploaded to a server and you don't need an account. Only map tiles and – for harbour names – rounded berth coordinates are requested from OpenStreetMap services. For the sail trim of the boat icon, Orca GPX requests rough wind data from Open-Meteo – only a grid over the trip area and the trip dates, no track points; only when “Load weather data for sail trim” is switched on.
Frequently asked questions
What is a GPX file?
GPX (GPS Exchange Format) is an open XML format for GPS data. A GPX track consists of track points with position and timestamp – exactly what navigation apps and chartplotters record while you are underway.
Can I combine multiple GPX tracks?
Yes. Create a voyage and add as many GPX files as you like. Orca GPX sorts them by start time and replays them as one journey; the time between two legs is treated like a stop in harbour.
Can I use GPX files exported from Orca?
Yes. The Orca app keeps a logbook per day that can be exported as GPX. These exports contain no speed; Orca GPX calculates SOG and COG from the positions. Orca GPX is an independent project and not affiliated with the maker of the Orca app.
Can I use GPX files from other chartplotters and apps?
Yes, as long as the track points carry timestamps. That is the case for standard GPX exports from most chartplotters, navigation and tracking apps. Without times a voyage cannot be animated.
Are my GPX files uploaded?
No. The files are read in your browser and stored locally there only. There is no server receiving them.
Can I create a video from my sailing track?
Yes. The “Video” export records the playback as a WebM video in 720p or 1080p; you set the pace (for example 1 s = 30 min). Recording runs in the browser and takes as long as the video.
Does Orca GPX work on iPhone and iPad?
Yes. Viewing, combining and the image export work in Safari on iPhone and iPad. Video export is designed for Chrome, Edge and Firefox on a computer; the export dialog tells you whether your browser can record.
Does Orca GPX calculate speed?
Yes. From position and time of consecutive track points Orca GPX calculates speed over ground (SOG) in knots, smoothed over several points, plus average and maximum. An adjustable distance correction compensates for one-minute points cutting corners.
What is SOG?
SOG stands for Speed over Ground – the boat's speed relative to the seabed, including current and drift. It is given in knots (nautical miles per hour); 1 kn = 1.852 km/h.
What is COG?
COG stands for Course over Ground – the direction the boat actually moves over the seabed, in degrees (0–360°). It can differ from the heading when current or wind set the boat sideways.
Is Orca GPX a navigation tool?
No. Orca GPX is intended to visualise and replay recorded voyages. It is not a replacement for nautical navigation software, official charts or proper onboard navigation. All values are calculated from GPS positions and serve illustration only.
Where do wind and weather come from – and how accurate are they?
They are hourly model values from the free weather service Open-Meteo (weather models from DWD, ECMWF and DMI, among others) on a grid of about 25 km, interpolated to your position. GPX files contain no weather data from on board – the values shown are therefore approximations, not exact values. Local effects such as funnelling between islands, shelter from land or the afternoon sea breeze are not in the model, so in narrow sounds the wind direction can be 40–60° off. TWA and sail trim are calculated from this model wind and your course over ground, not from boat data.
How does Orca GPX detect tacks, gybes and motoring?
A tack or gybe is a course change of at least 60° within a minute under sail; the wind direction decides whether the bow or the stern went through the wind. Motoring shows as very even speed over at least 20 minutes, speed in a calm, and weaving just before the berth or anchorage. Regular tacking counts as beating, not motoring. Both are estimates: in the timeline you can switch any detected section to “Under sail” or “Not set”, and motoring detection can be switched off entirely under Settings → Boat.
Which keys are there?
Space plays and pauses, ↑ ↓ (or ← →) change the speed, Shift + ← → jumps an hour. A and D jump to the previous or next harbour, S to the start, W to the last harbour of the voyage. P switches presentation mode on and off, Esc exits it. The digits 1 to 0 toggle displays from the settings – just try them.
Orca GPX is an independent, private GPX visualisation tool and is not affiliated with Orca Technologies, the maker of the Orca app. “Orca” is a trademark of its owner and is used here descriptively only.