Privacy Policy

Effective July 15, 2026 · Developer Working Model LLC

# 1.0Overview

Slackwater is a tides and weather app for the U.S. coast, available as an iOS app (iPhone and iPad) and at slackwater.app. Your privacy matters to us. This policy explains what data Slackwater handles, what it does not, and your choices. The short version: Slackwater has no user accounts, shows no ads, runs no tracking, and never sells your data.

# 2.0Data We Collect

Slackwater does not collect, transmit, or store personal data on our servers, and it does not require an account. Your preferences and saved places are kept locally on your device. To show you live tide and weather information, the app makes network requests to public data sources, described in section 2.3.

2.1What stays on your device

Your saved or favorite stations
Display preferences (theme, wind speed units, map layer settings, playback speed)
Your notification preferences (which reminders you've enabled and their settings)
The last station or view you had open, and any default map view you've set

This information is stored locally on your device and is not transmitted to us. Removing it is described in section 5.0.

2.2Location

If you grant location permission, Slackwater uses your device location only to show your position on the coast map, while you are using the app. Your location is handled on-device by Apple Maps and is never sent to us or to any third party. The app's tide and weather data is fetched using the fixed coordinates of NOAA stations, not your location. Location access is optional — the app works without it, and you can change this any time in your device Settings.

2.3Network requests and data sources

To display tides, water levels, weather, wind, radar, and sun & moon times, Slackwater requests data from the following services as you use it:

Slackwater API (api.slackwater.app) — our own server, which fetches and caches public data from NOAA CO-OPS (tides & water levels), the National Weather Service (forecasts), and the U.S. Naval Observatory (sun & moon). It receives only the station IDs and fixed station coordinates needed to answer a request.
Open-Meteo (api.open-meteo.com) — wind and precipitation forecast grids for the coastal region.
RainViewer (api.rainviewer.com) — weather radar tiles.
Apple MapKit — the base map and tiles, provided by Apple.

As with any internet request, the providers above necessarily receive standard technical information, including your device's IP address and the request itself. This is inherent to how the internet works; it is used only to deliver the data you asked for. We do not use it to identify you, build a profile, or track you across sessions, and our server stores only public tide and weather responses (no personal data) in its cache. Data delivered by Apple and the third-party services above is also subject to their respective privacy policies.

If you enable tide reminders, some of these same requests may run periodically in the background to keep those reminders current. This uses only the fixed coordinates of your saved stations — never your device location — and transmits nothing about you.

2.4Apple services

App Store: downloads and updates are handled by Apple. We do not receive your payment information or Apple ID.
Subscriptions (StoreKit): Slackwater's subscription is processed entirely by Apple. We receive only your subscription status (active or not) — never your payment details or Apple ID.
Crash Reports (App Store Connect): if you have opted in to share analytics with developers in iOS Settings, Apple may share anonymized, aggregated crash and performance data with us. It contains no personally identifiable information. You can control this under Settings > Privacy & Security > Analytics & Improvements > Share with App Developers.

2.5Diagnostics and problem reports

To help us find and fix crashes and performance problems, Slackwater uses Apple's MetricKit to gather diagnostic data — such as crash and hang reports and app performance metrics — on your device. This information is kept only on your device and is never sent automatically.

It leaves your device only if you choose to send it. Tapping "Report a Problem" in Settings opens a pre-addressed email to us with a diagnostics report attached, which you can read, edit, or cancel before sending. The report contains technical information only — your device model, iOS and app version, recent in-app log messages, and the MetricKit reports above. It does not include your name, an account (there is none), your precise location, or the content of what you view. You decide whether to send it.

2.6Notifications

If you enable them, Slackwater can send tide, solunar, and daily-briefing reminders that you configure in Settings. These are calculated and scheduled entirely on your device using local notifications — there is no push server, and turning them on transmits nothing to us.

2.7Data we do NOT collect

No accounts or sign-ins
No advertising, ad identifiers (IDFA), or ad networks
No third-party analytics or tracking SDKs
No selling or sharing of data for advertising or marketing
No access to your contacts, calendar, photos, microphone, or camera
No transmission of your device location to us or anyone else

# 3.0Data Sharing

We do not sell your data and we do not share it with third parties for advertising or marketing. The only data leaving your device is the network requests described in section 2.3 (made to deliver the information you requested) and, if you choose to send one, the diagnostics report described in section 2.5.

# 4.0Data Storage and Security

Your preferences, saved places, and any on-device diagnostics are stored in your device's local storage. Our server caches only public tide and weather data and is hosted on Cloudflare's infrastructure. Because we hold no accounts and no personal data, there is no personal profile to breach.

# 5.0Data Deletion

You can remove saved stations and reset preferences within the app at any time. Uninstalling Slackwater removes all of its locally stored data from your device.

# 6.0Children's Privacy

Slackwater is a general-audience utility and is not directed to children under 13. Because the app collects no personal data from any user, there is no children's data to protect.

# 7.0Changes to This Policy

We may update this policy from time to time. Changes will be posted on this page with an updated effective date.

# 8.0Contact

If you have questions about this privacy policy, contact us at [email protected].