Privacy Policy
Tidemark for iOS. Last updated 24 September 2026.
Tidemark collects no personal data. There is no account, no analytics, no advertising and no tracking of any kind. Nothing you do in the app is sent to the developer.
What stays on your device
The app stores your selected station, your favorite stations, and your unit and clock preferences, plus a count of the days you opened the app (used only to decide when to ask for a rating) and when it last tried to download each station's yearly predictions; those live in the app's own container and are included in your device backup if you use one. The tide predictions it downloads are kept separately in the app's cache directory, which iOS excludes from backups. None of it reaches the developer or any third party.
Location
Tidemark asks for location access only when you tap Find nearest stations in the station picker. The coordinate is used once, on your device, to sort the built-in station list by distance. It is not stored, not logged and not transmitted anywhere. If you never tap that button, the app never requests location. You can revoke access at any time in Settings, and the rest of the app continues to work.
Calendar
When you add a low tide to your calendar, Tidemark opens Apple's own New Event screen with the event filled in. You choose the calendar and tap Add. The app does not ask for calendar access and cannot read, change or see your calendars or events.
Network requests
To show tide predictions the app requests them from the NOAA Center for Operational Oceanographic Products and Services at api.tidesandcurrents.noaa.gov. Each request contains a station ID (the one you are viewing in the app or a widget, or one of your favorites), a date or time range and an application identifier. Requests are for tide predictions and, where a station has a sensor, its latest water temperature. It contains no personal identifier, no device identifier and no location. NOAA operates that service and its own privacy practices apply to it; see the NOAA privacy policy.
Children
Tidemark is suitable for all ages and collects no data from anyone, including children under 13.
Changes
If this policy ever changes, the revised version will be posted on this page with a new date. Since the app collects nothing, any change would be a clarification rather than a new use of data.
Contact
Questions about this policy: mybosseatpoop@gmail.com.