Mareas
Last updated: 4 September 2026
The short version. Mareas has no accounts and no servers of mine. The only thing that leaves your iPhone is a pair of coordinates, sent to a public tide forecast service so it can tell the app what the sea is doing there.
There are no accounts, no tracking, no advertising and no analytics in this app. Nothing about you is sold or shared with data brokers. Ever.
What the app handles, and where it goes
This is the complete list. If something isn't in this table, the app doesn't touch it.
| What | Where it goes | Why |
|---|---|---|
| Your location, if you allow it | Open-Meteo, as a latitude and longitude | To fetch the tide forecast for the water nearest you. Sent per request, not stored. |
| What you type in the search box | Apple's MapKit search service | To autocomplete place names as you type. Handled by Apple under Apple's privacy policy. |
| Coordinates of a place you searched | Open-Meteo, as a latitude and longitude | To fetch the tide forecast for that place. |
| Favourites, recent places, cached forecast | Stays on your iPhone | So the app and its widget open instantly and still work with no signal. |
Permissions the app asks for
Location — While Using the App
Optional. Only used to pick a starting point near you. Deny it and the app works exactly the same, you just search for places by name instead.
Who else is involved
I have no servers. Where the app needs something it can't compute on your iPhone, it asks one of these services directly:
Tide, sea level and weather data. Free and open, no account and no API key, so there is no identifier attached to the request. Data licensed CC BY 4.0.
Apple MapKit
Place search and autocomplete, built into iOS.
How long anything is kept
On your iPhone, for as long as you keep the app. I keep nothing, because I have nowhere to keep it — there is no backend, no database and no log of who uses the app. The third parties above keep what their own policies say they keep.
Deleting your data
Delete the app. iOS removes its storage, its caches and its Keychain items along with it, and there is no copy anywhere else. If you'd rather clear things without deleting the app, the app's own settings let you remove what it has stored.
Your rights
Under the GDPR you have the right to access, correct, delete and export your personal data, and to object to its processing. In practice, for this app there is almost nothing for me to act on: I hold no copy of your data, so there is no account of yours for me to look up.
What you can do yourself, right now, without asking me:
- Delete everything the app holds by deleting the app from your iPhone. iOS removes its storage, its cache and its Keychain items with it.
- Withdraw any permission in Settings → Privacy & Security, or in the app's own row in Settings.
If you want to exercise a right anyway, or you think I've got something wrong, write to hola@nachodivasson.com and I'll answer within 30 days. You can also complain to the Spanish data protection authority, the AEPD.
Children
This app is not directed at children under 13, and I do not knowingly collect anything from them.
Changes to this policy
If the app starts doing something new with your data, this page changes before the update ships, and the date at the top changes with it. I don't make changes retroactively.
Who is responsible
Ignacio Divasson, an individual developer based in Spain, is the data controller for this app.
Contact: hola@nachodivasson.com