CoveGuard
The sailing copilot that thinks ahead.
CoveGuard watches your anchor while you sleep, shows how the wind will blow in every bay and warns you before things go wrong. In the Adriatic, Greece, Italy, France and Spain — even without signal.
Android · English and Czech · safety free forever
No iPhone yet — we're sorry. Our goal is an iOS version by summer 2027.
A principle we won't move on
You never pay for safety here. And you never will.
Anchor watch, distress calls and man overboard work for everyone — no subscription, no trial, no payment. Downloaded maps stay free too.
Paid extras will come one day, so the app is still here in five years. They will never lock away what you use today — a safeguard right in the app's code makes sure of it.
Anchor watch
You sleep. It doesn't.
Tell it where the anchor is and how much chain you let out. The app watches whether the boat stays in the safe zone — all night, with the phone locked.
- A zone from your chain and depth. Or draw it to the shape of the bay.
- An alarm only when the boat really leaves. Two reliable positions outside the edge. A single GPS jump won't wake you.
- It rings like an alarm clock. Even with the phone on silent and over the lock screen.
- If the GPS drops out, it doesn't go quiet. It tries to get the position back and tells you — with a gong or the siren.
- Set it up your way. When the siren should stop, whether it gets louder, how long to wait in calm weather.
- In the morning, see what the boat did. The track, how far it swung and how the pressure went.
A simplified, sped-up demo, to scale (the boat is drawn a little larger). The yellow dashed line marks the “near the edge” band; the blue dot on the boat is the phone.
The watch in the app
For the curious: how exactly the watch decides
- A reliable position = the phone measures it to within 20 m or better, and it is a new measurement, not an old position repeated.
- Stuck GPS: sometimes a phone keeps sending the same position even though it is no longer measuring. A boat at anchor always moves at least a little, so a position that doesn't move at all stops counting as reliable after a minute. In the settings you can shorten this to 30 or 20 s: a stuck GPS is noticed sooner, but in a dead calm it may report a lost position needlessly.
- A GPS jump that would mean more than 3 m/s has to be confirmed by the next position. A lone jump doesn't count; a boat really moving off gets confirmed position by position.
- GPS loss: 45 s without a reliable position. The watch tries to restart location, sounds a gong after a minute, then your chosen signal — a gong or the siren. In calm weather (forecast, radar, lightning and the nearest station) it can wait longer; if the weather is unknown, it counts as rough.
- After an alarm the siren keeps going until you silence it — or, if you choose, stops by itself after a few minutes back in the zone. If the boat keeps moving away after you silence it, it comes back sooner. The volume can build up gradually.
- Before it starts it plays a test tone (you can choose to skip it) and checks the boat isn't already outside the edge. Without location set to “Allow all the time” it won't start.
- Restarts and updates: the watch survives an app update and, after a phone restart, comes back by itself as soon as you first unlock the phone. A notification in the status bar shows the watch is running.
- A critical battery (10%) has its own loud sound, different from the siren — you can tell it's the battery, not the anchor.
Remote watch — Konoba
At dinner? The crew ashore keeps watch.
A second phone on the same account (say, in your pocket at dinner) sees the boat live and gets a warning when something happens — even if the boat stops reporting its position. It can silence the siren remotely, but it can't switch the watch off.
Weather warnings
It warns you ahead of time, not when it's too late.
Five of these our server checks every 5–15 minutes, even with the app closed. The pressure drop is measured right on your phone.
Weather warnings are not the anchor alarm. The siren only sounds when the boat really leaves the zone.
For the curious: exact thresholds (warning / alarm)
- Wind turning 45° / 90° within 6 hours (an alarm only with at least 12 knots).
- Gusts 8 / 15 knots stronger than at the last check.
- Wind into the open side of the bay 15 / 25 knots.
- Bora from the north-east with gusts of 28 / 45 knots within 12 NM of you.
- A storm cell (core from 8 mm/h, area from 25 km²) passing closer than 6 km and reaching you within 90 min (critical within 20 min).
- Pressure falling 3.6 hPa in 3 h or 2 hPa in an hour.
Weather
For every sea, the most detailed model.
No model is best everywhere. For each sea we take the one that computes it most finely. Automatic mode blends them for wherever you're looking on the map.
- Gusts straight from the model. We don't guess them from the mean wind.
- What's raining and flashing right now. Radar, satellite rain where radar can't reach, and lightning from space.
- You see how old the forecast is. Without signal it shows the last one downloaded — and doesn't pretend it's fresh.
- Which forecast to trust today. We compare the models with what weather stations measured.
- All of Europe from afar. A weather overview, isobars and frontal charts.
- Tides and currents on the Atlantic and in the Channel.
Weather in the app
Try it: which model covers where
An island in a westerly wind, a 30 × 30 km square, colours as in the app. A finer grid catches the lee behind the island and the faster wind off its tips — a coarse one smears them. The streaks show how fast the model says the wind blows there.
For the curious: weather sources and how often we fetch them
We don't wait for fixed times — every 15 minutes we ask each source whether it has a newer forecast. If it does, we fetch it straight away.
| Source | Where | New forecast |
|---|---|---|
| ALADIN‑HR · 2 km (DHMZ) | Croatia | 2× a day |
| ICON‑2I · 2 km (ItaliaMeteo) | Italy, southern Adriatic, Ionian Sea | 2× a day |
| AROME · 2.5 km (Météo‑France) | France, Corsica, Sardinia, Spain except Andalusia | 8× a day (we take 4) |
| ICON‑EU · 7 km (DWD) | Europe | 4× a day |
| ECMWF and GFS · 0.25° | the whole world | 4× a day |
| OPERA radar and Italian DPC | Europe | every 15 min |
| Satellite rain and lightning (EUMETSAT) | Mediterranean and Atlantic | continuous |
| Official warnings (MeteoAlarm, DHMZ) | all countries | every 5 min |
Why the Croatian ALADIN and not the one other apps show: ALADIN is a family of models, and over the Adriatic you usually see the Czech version built for Central Europe. We take ALADIN‑HR straight from Croatia's DHMZ, which issues the official Adriatic forecasts — and it computes the wind on an even finer grid because of the bora.
Anchorages and bays
How sheltered is this bay — today?
Every bay has a shelter score that changes with the forecast — not one grade from a pilot book.
- Seabed from data. Mud, sand or weed from the European seabed map.
- Where you mustn't anchor. Protected seagrass and official no-anchoring zones — in France also by the length of your boat. Once the data for the area is downloaded, the check works without signal.
- Crews' experience. Ratings, photos and “is there space?” from people on the spot.
- An honest “we don't know”. Where we have no data, we don't make anything up.
Try it: where is the wind from?
A demo bay open to the south. The real score also weighs wind strength, gusts, waves and the shape of the coast.
Ship's log
A logbook that writes itself.
The boat gets moving and the passage starts recording. In the morning you have the track, the stops and the night at anchor — without tapping a thing.
Engine hours only with the engine
Never worked out from speed — a sailing boat under sail doesn't rack up engine hours.
The track survives a crash
Every position is saved at once. On the next start the app asks what to do with the unfinished record.
Replay the passage
Slide a finger along the timeline and see course, speed, wind and pressure.
It notices stops
Swimming, shopping, fuelling — it offers to log them.
Place names, not coordinates
“Off the island of Vrgada” — even without signal.
Exports like a real logbook
A4 PDF, one day per page. Or CSV and GPX.
For the curious: when recording starts and stops
- Recording starts after 60 s of steady speed between 2 and 18 knots (once running, it keeps going faster too).
- A longer stop is offered as a stop after 20 minutes (adjustable 10–45 min).
- The passage pauses after 10 minutes below 0.7 knots and closes after three hours stopped or at 2 a.m.
- You never overwrite the original GPS track — trimming, splitting and joining can all be undone.
- The log keeps the last year and deletes older records, so don't leave exporting too late.
And the rest
Everything else a passage asks for.
Boat instruments
The app finds the plotter's Wi‑Fi gateway by itself. Speed, depth, wind and AIS from the boat.
Route planning
Under engine or sail with tacking, with time and fuel estimates.
Go or wait?
Wind, waves and warnings along the route in one recommendation — with the reason.
Distress and man overboard
SOS with the call ready to read, getting back to a person in the water, SMS without internet.
Boat and crew
Boat profile and a safety briefing for the crew — your Croatian, Italian, Slovenian or German crew can read it too.
Places with a story
What a cape, island or lighthouse is about — over 20,000 places, in English and Czech.
What's around me (augmented reality – AR)
Point the phone at the horizon and the app names the lighthouse, island or town. Lighthouses in the Adriatic for now, islands and towns in Greece.
Offline handbooks
Collision regulations, buoyage, first aid and VHF channels.
Fuel and services
Fuel stations, shops, water, repairs and pharmacies on the map.
Boats nearby
Who's around and chat with crews. Others see you with your position rounded to about 200 m — one switch turns it off.
No signal
Maps, handbooks and the downloaded forecast work offline.
In sunlight and at night
Day, night and red tactical mode. Try it below.
A few screens from the app
Readable in direct sunlight.
Where it works
The Adriatic is home water. The other seas, we describe honestly.
Most of the app works the same everywhere. What differs by country, or is still missing, is in the table.
The same everywhere
- Anchor watch and the shore watch (Konoba)
- Distress calls with the rescue centre for where you are
- Forecasts from several models, Automatic mode and weather routing
- MeteoAlarm warnings and lightning from space
- Anchorages and bays with a shelter score for the wind
- Offline maps, places with a story, logbook and voyages
What differs by country
| Adriatic | Greece | Italy | France | Spain and the Atlantic | |
|---|---|---|---|---|---|
| Most detailed weather | ALADIN 2 km (south: ICON‑2I 2 km) | Ionian Sea 2 km, Aegean ~7 km | ICON‑2I 2 km, AROME in the west too | AROME 2.5 km | AROME 2.5 km, Andalusia ~7 km |
| Weather stations | DHMZ | airports and ΕΜΥ (delayed) | MeteoHub, ISPRA, airports | Météo‑France | AEMET, MeteoGalicia, SOCIB, Euskalmet |
| Radar and storm alerts | ✓ | partly | ✓ | ✓ | ✓ |
| Seabed type at the anchor | ✓ | not yet | ✓ | ✓ | ✓ |
| Protected seagrass | ✓ | not yet | not yet | not yet | Balearics, Valencia |
| Anchoring rules and bans | national parks | Delos | not yet | prefecture orders, also by boat length | Balearics |
| Anchorages | also marinas and buoy fields | OpenStreetMap only, no marinas or buoys | ✓ | fewer on the Atlantic | fewer on the Atlantic |
| Tides and currents | not needed | not needed | not needed | Atlantic and Channel | Atlantic |
| Official warnings | DHMZ + MeteoAlarm | MeteoAlarm | MeteoAlarm | MeteoAlarm | MeteoAlarm |
Good to know
- An empty spot on the no-anchoring map doesn't mean anchoring is allowed there.
- Where the radar can't see, the app says so on the bay card.
- Tides come from a model, not a harbour table — so for depth we only say “at least”.
- In Greece, rocks and wrecks are raw community data and ferry corridors are still missing.
- Bora alerts are for the Adriatic only — the bora doesn't blow elsewhere.
- Portugal and Malta aren't covered yet. Where next depends on where you sail.
Why CoveGuard exists
We got fed up with safety being sold.
Paid charts miss the details that matter at sea — or charge a lot for them. So we put the bays, depths and warnings together ourselves, legally and with the community. What keeps you safe at sea stays free.
Our own seabed map
From depths measured by the community's boats. What we measure together stays shared.
AIS for everyone
We can do it technically. Once enough boats share their positions, everyone will see them — at no extra cost.
More seas, led by you
After the Adriatic came Greece, now Italy, France and Spain. We'll go where we're needed.
We are an aid, not a replacement for navigation. We can work out a route, but navigation needs official charts and approved instruments. CoveGuard doesn't replace charts, VHF or the skipper's judgement.
Free beta
Take us to sea.
CoveGuard is free on Google Play for Android. In return we'd like honest feedback from people who really sail. Those who are with us from the start will keep better terms with us for good.
Scan with your phoneWe have nothing for iPhone yet, and we're sorry about that. We're finishing Android first; our goal is an iOS version by summer 2027.
Where the data comes from
We tell you what you're trusting.
Every layer on the map shows where its data comes from. In detail in the Licences.