Last updated: 28 July 2026
Tidey is a tidal-stream chart app for sailors. This policy explains what data the app uses and, just as importantly, what it doesn't.
If you grant permission, Tidey uses your device's location to show your position on the chart relative to the tidal flow arrows. This location data is used only on your device, in real time, to draw your position on the map. It is never transmitted to us, stored by us, or shared with any third party. You can deny or revoke location permission at any time in your device's Settings; the app remains fully usable without it.
Tidey has no user accounts and no sign-in. We do not collect your name, email address, contacts, or advertising identifiers. We do not use analytics, advertising, or crash-reporting SDKs, and we do not sell or share your data with third parties.
Tidey offers an optional paid subscription that unlocks the full-resolution tidal model. If you subscribe:
The app ships with a low-resolution tidal dataset that works entirely offline. Subscribers additionally download the full-resolution dataset from our own server, hosted on Cloudflare. When the app makes that request it sends the anonymous subscription identifier described above, so the server can confirm the subscription is active before releasing the data. As with any internet request, Cloudflare processes your device's IP address in order to route it.
We do not log that identifier against your activity, and the request contains no location data, no personal details, and nothing about how you use the app. Once downloaded, the dataset is stored privately on your device and re-used offline.
Your app preferences (units, map style, chosen course, and similar settings) are saved locally on your device using standard iOS/Android app storage, so they persist between sessions. This data never leaves your device and is deleted automatically if you uninstall the app.
The map itself is drawn using Apple Maps (iOS) or Google Maps (Android), subject to their own privacy policies. If you enable the optional nautical chart overlay in Settings, the app requests map tiles directly from OpenSeaMap, a free open seamark-data project; that request is a standard image fetch and does not include your identity or location beyond what's inherent in requesting the visible map area. This overlay is off by default and can be toggled in Settings.
Tidal stream predictions shown in the app are a model, not an official navigational product, and should not be used as the sole basis for navigation decisions. See the in-app disclaimer for details.
Tidey is not directed at children and does not knowingly collect personal data from anyone, including children.
If this policy changes, we'll update this page and the "Last updated" date above.
Questions about this policy, or about your data, can be sent to us through the "About" screen in the app.