Privacy notice

What SwimSignal collects, and what it does not. Last updated 30 September 2026.

Who is responsible

SwimSignal is run by one person, the owner of the GitHub account ethanbuckley, who is the controller for the personal data described here.

For anything private, including a data-protection request or a complaint, email ethan@ethanbuckley.me.uk. A complaint is acknowledged within 30 days. For general questions you can also open an issue on the project's GitHub repository; issues are public, so do not put anything personal in one.

The short version

• No accounts, no cookies and no advertising. There is no analytics script and no third-party tracking.
• Your saved spots and your location stay on your device.
• Opening the site sends your IP address to the services that supply its files, as it would for any website. They are listed below.

Who sees your IP address

When you open the site, your browser fetches files from these services, and each one receives your IP address and basic details of your browser:

• GitHub, which hosts the site (GitHub Pages). GitHub logs these requests for its own security purposes and is responsible for those logs. Its privacy statement applies.
• The OpenStreetMap Foundation, for the map images. Its privacy policy applies.
• unpkg.com, for the map library (Leaflet).

SwimSignal asks for these files because the page cannot show its map or run without them. That is the legitimate interest these requests rest on. SwimSignal itself receives no personal data from them and keeps no logs. These services may handle your IP address outside the UK, under their own safeguards.

Your location

The list of spots can be sorted by distance from you. Your browser asks for your location only if you choose "Near me". The page uses it to order the list and for nothing else: it is not sent to SwimSignal or to anyone else, it is not stored, and it is gone when you close the page. Choosing "Near me" does not move the map, so the map images fetched from OpenStreetMap do not reveal it either.

Saved spots

If you press Save on a spot, its identifier is kept in your browser's local storage, so the spot shows on your Saved page and at the top of the list. It stays on your device: it is not sent to SwimSignal or to anyone else. Clearing this site's data in your browser removes it. On an iPhone, Safari and a Home Screen app keep separate lists.

"Share this list" makes a link holding the identifiers of your saved spots, after a # that browsers do not send to the site. Anyone you send the link to can see which spots are on the list.

Offline copy

After your first visit, the browser keeps a copy of the page, its icons, the map library and the latest forecast (using a service worker), so the site still opens without signal. The copy holds only what every visitor downloads, and nothing about you. You can turn it off, which also deletes it, under "Saved spots, offline use and your data" at the bottom of the home page. Clearing this site's data removes it too.

If you email

If you email the operator, your address and what you write are used only to reply and to deal with any request or complaint. The basis is legitimate interests, or a legal obligation for a data-protection request. They are kept only as long as that takes, then deleted, and are never shared or sold. The operator's email provider holds them in the meantime.

Feedback

The feedback form prepares an email on your device. It does not submit or save what you type. Nothing is sent to the operator until you send the email yourself; the email handling described above then applies. The copy button puts your draft on your device’s clipboard. You can also choose to open a GitHub issue; issues are public and GitHub’s privacy statement applies. Do not put personal information in a public issue.

If alerts are added

A planned feature would send a notification to your phone or computer when a saved spot's forecast turns high. If it is added, this notice will be updated first. It would store only what is needed to send those notifications, never share or sell it, and you would be able to turn it off at any time, which deletes it.

The server version

SwimSignal's code can also run as a server that forecasts any point you click. No such server runs for this site. Whoever runs one receives the coordinates you click and your IP address, and keeps a log of the forecasts issued (the coordinates, the time and the forecast values, with no IP address or identifier) to score their accuracy.

Your rights

UK data protection law gives you rights over personal data about you, including to be told what is held, to have it corrected or deleted, and to object. SwimSignal holds none, as described above; ask GitHub about its logs. You can complain to the operator by email (above) and to the Information Commissioner's Office.