Privacy Policy
Effective September 2026, updated October 2026. This page is informational and is not legal advice. A qualified lawyer should review it for your jurisdictions.
Slackwater is built to collect as little as possible. Your saved spots, settings, and any logs stay on your device and sync only through your own iCloud account. There is no Slackwater server holding your personal data. We do not sell your data, we do not run ads, and we do not track you across apps or the web.
Who we are
Slackwater is published by Handler Labs LLC. For privacy questions, contact support@handlerlabs.app.
What stays on your device
Your spots, alert settings, units, tide windows, and any session log are stored on your device using Apple's SwiftData and sync to your private iCloud database through Apple's CloudKit. We cannot read this data; it lives in your Apple account. You can export or delete it at any time, and removing the app removes the on-device copy.
Location
If you use "tides near me," the app asks for your approximate location. It is used on your device to rank nearby tide stations. We do not store your location, and it is never used for tracking. You can deny or revoke this permission and still use the app by searching for a spot.
Marine conditions
Marine conditions is a Premium feature that reads live observations from NOAA's National Data Buoy Center. Readings are fetched on demand through a stateless proxy that passes a tide-station coordinate, not your device location, and returns wind, swell, water temperature, and pressure for the nearest reporting buoys. The proxy stores nothing and keeps no logs beyond anonymous, short-lived edge caching.
Wind alerts
Wind alerts, a Premium feature for US stations, read the National Weather Service's hourly wind forecast through the same proxy, again passing only the tide station's coordinate. The alerts themselves are scheduled as local notifications on your device.
Live water level
At a station whose national tide-gauge agency publishes a live reading, the app shows how far the real water is from the prediction. It asks the same stateless proxy for the latest reading of that gauge, passing the station's identifier and coordinate, not your device location. The proxy fetches the agency's public feed, returns the reading and stores nothing.
Sea temperature and marine warnings in Japan
At a Japanese station the app shows the Japan Meteorological Agency's latest sea-surface temperature for the nearest point of its analysis, and the wave, storm-surge and tsunami warnings and advisories JMA has in force for the station's area. It asks the same stateless proxy for them, passing the station's coordinate and JMA's code for its area, not your device location. The proxy fetches JMA's public data, returns it and stores nothing. The warnings are shown in the app only; nothing is pushed to you.
These, marine conditions and wind alerts are the only parts of the app that use the network; the tide and solunar core needs no network at all.
Subscriptions
Purchases are handled entirely by Apple through StoreKit. There is no subscription middleman: no third-party purchase service receives anything about you, and we never see your payment details. Apple's standard payment and privacy terms apply to the transaction.
Diagnostics
The app contains no analytics SDK and no crash-reporting SDK. Product events are written only to your device's own system log and never transmitted anywhere. For reliability we rely on what Apple already aggregates for every developer, in App Store Connect and Xcode, which is anonymous and which you control in your iPhone's privacy settings. This is why the app's App Store privacy label reads "Data Not Collected."
Your rights
Depending on where you live, you may have rights to access, correct, delete, or export your data, and to object to or restrict certain processing. Because your data lives on your device and in your iCloud, you can exercise most of these directly in the app and in your Apple account. For anything else, contact us at the address above. California residents have rights under the CCPA and CPRA, and we do not sell or share personal information as those laws define it.
If you are in the EU, the EEA, the UK or Switzerland
Handler Labs LLC is the controller for the little personal data described here, and you can reach us at the address above. We hold no account, profile or analytics data about you. The only personal data that reaches a system we operate is your device's IP address, which arrives with each request the app makes for live water level, Japanese sea temperature and warnings, marine conditions or wind alerts, as it does with any web request. It is used only to answer that request (Article 6(1)(b) GDPR, providing the feature you asked for, and Article 6(1)(f), our legitimate interest in running the service securely), and we do not log or keep it.
The proxy runs on Cloudflare, which processes these requests for us as a service provider under its data processing addendum and may do so in the United States. Cloudflare is certified under the EU-U.S. Data Privacy Framework, its UK Extension and the Swiss-U.S. Data Privacy Framework. Your iCloud data is held by Apple under your agreement with Apple, and purchases are processed by Apple as the seller.
You have the right to access, correct, erase, restrict or port your personal data and to object to its processing. Because we keep none, most requests are answered by the app itself and your Apple account, but we will answer any request sent to the address above. You can also complain to the data protection authority where you live or work (in the UK, the Information Commissioner's Office).
Children
Slackwater is not directed to children under 13 and does not knowingly collect their data.
Changes
If this policy changes in a meaningful way, we will update the date above and, where appropriate, note it in the app.
Tide predictions are estimates for reference only. They are not for navigation or life-safety decisions. Always consult official tide tables (NOAA's in the US) and nautical charts.