On the watch
The watch app records your activity (GPS track, speed, heart rate) on your watch and saves it to your Garmin account through Garmin's own sync. We receive nothing from Garmin. The watch app talks to our server only to check its license, online through Garmin Connect: when a trial starts or the license is checked, it sends the app name, the watch app's device id and a public key the watch app creates; older watch app versions also send a license code when one is activated. If the watch is linked to your SlalomSurfing account, the answer comes from your account's subscription. If you use the SlalomSurfing mobile app, the watch app passes your sessions to it over Bluetooth (see below).
Your account in the mobile app
If you use the SlalomSurfing mobile app, we keep your account: e-mail address, name (if you give it), how you sign in (password stored only as a secure hash, or Apple / Google sign-in) and the rider profile you fill in: nationality, sail number, club and gender (each optional). We also keep a list of the watches that synced with the app (watch app, device id, watch model, first and last sync).
Recording with the phone. You can also record a session with the phone, without a watch. Between Start and Stop the app records time, speed, precise GPS position and heading once a second, also while the screen is off; nothing is recorded outside a session. The app asks for the location permission “while using the app”, never “always”. Heart rate is recorded only from a heart-rate strap you connect. The session is kept on your phone and goes to your account only with the session backup consent below, for the same purposes and with the same retention as watch sessions. Phone sessions are marked PHONE and, with the consents below, enter spot rankings and challenges like watch sessions.
Sessions from other watches. You can bring sessions of another watch into the app in two ways. You can import a FIT file you exported (for example from COROS, Polar Flow, Suunto or Garmin Connect); it goes to our server and becomes a session in your account, under the session backup consent below. Or, with a separate consent (“Import from my other watch apps”), you can connect your Polar account once (and your COROS account in the same way once that integration is approved; it is pending approval): after each sync the provider tells our server, and our server reads only your water-sport activities (windsurfing, kitesurfing, sailing, surfing, paddling and similar) - time, speed, GPS position and heart rate per second, the sport and the watch's name; runs, rides, sleep and daily health data are never read. The access the provider gives us is stored encrypted on our server and never reaches the phone. Each imported activity becomes a session in your account, backed up like your other sessions; if a session of our watch app or of the phone covers the same time, that one is kept and the import is removed. You can disconnect an account at any time on the Connected services screen (we stop reading and delete the access); withdrawing the consent disconnects every account; sessions already imported stay until you delete them. Polar and, once connected, COROS remain responsible for the data on their side under their own privacy policies.
Session backup. With your consent, the mobile app copies each session - recorded with your watch or with this phone - and backs it up to your account on our server, so your sessions come back on a new phone: time, speed, GPS position and heart rate per second, the session values computed on the watch or the phone (speed runs, jibes and tacks, wind axis), your gear choice and, for race sessions (RacePRO), the start line, marks and countdown events, together with a short summary of each session (date, spot, the main values). Because heart rate can count as health data, the app asks for your explicit consent before the first backup. Without it nothing of your sessions is sent to us: they stay only on your phone, and restoring on a new phone, sharing with connections, spot rankings and replay videos do not work. We use the backup to show you your own sessions, to restore them and for what you choose to share (see below).
This data is stored on our servers at Hetzner in Germany (Falkenstein). It is visible only to you, unless you share it (see below). It is kept in active storage until you delete a session or your account (for recovery backups, see Encrypted recovery backups). You can withdraw the backup consent at any time in the app (Privacy and sharing). The app then first downloads to your phone every session that is only on your account; after that your backups are deleted from active storage on our server, which cannot be undone; encrypted copies can remain in recovery backups for up to 30 days (see Encrypted recovery backups). This consent covers your sessions only: your account information stays in the general recovery backups. The sessions on your phone stay.
Deleting your account (in the app: Settings → Delete account, or by writing to us) deletes from active storage on our server at once: your account and profile, backed-up sessions and their summaries, what you shared and your sharing settings, your spot-ranking and challenge results, your group-training memberships and the free trainings you lead, the comments you wrote and the comments on your sessions, your connections and blocks, replay videos, your watch list, the problem reports you sent, your push tokens, notification settings and notification list, and the notifications you caused in other riders' lists. Sessions on your phone stay on your phone. The subscription records our server keeps for your account (see When you subscribe) are deleted too, unless a legal obligation requires us to keep them; a store subscription keeps running until you cancel it in the App Store or Google Play. The payment and transaction records of the purchase are kept by Apple or Google under their own terms. A watch app's trial and license record (app name, device id, public key; see On the watch) belongs to the watch, not to your account, and stays. We keep: the record of each consent you gave or withdrew, for 5 years without your account id; copies of reported comments (see Comments); and notifications from before 21 October 2026 that other riders received, until they expire (at most 90 days). Your account's dedicated backup folder is deleted from our server when your account is deleted. Its Cloudflare R2 copy is scheduled for deletion during the next backup synchronization, which normally runs every 15 minutes. Failed deletion attempts are retried. Encrypted copies in historical and shared recovery backups can remain for up to 30 days (see Encrypted recovery backups).
Encrypted recovery backups
For disaster recovery, we maintain encrypted backups of application data on our servers and copy encrypted backup files to Cloudflare R2 (Cloudflare, Inc.). These backups may include account information, session data, profile details, sharing and coaching records, and other information stored in the application - account information is included even if you have not given the session backup consent. The files are encrypted before transfer to Cloudflare R2. Object names may contain account and session identifiers. Decryption requires a private key held separately from the backup infrastructure. In addition, a full copy of the database is kept on the same Hetzner servers for up to 2 days; it is not encrypted and is not copied to Cloudflare R2.
Deleting data from the active application does not immediately remove every copy from recovery backups. Our backup retention policy is designed to remove deleted data from recovery copies within 30 days. During this period, encrypted copies may remain in historical or shared backup archives.
Sharing with other riders
Connections. You can connect with other riders. Connected riders see each other's name, sail number, club and gender. Nothing of your sessions is shared by default: you choose which session values (for example top speed, 500 m, jibes) your connections may see, or share one session or one value on purpose. To show a shared value, your connection's phone receives the second-by-second speed of that session, or of a short part around a shared turn or value (at most 10 minutes). It receives your real positions only if you share the map; otherwise the track is shifted east on the map by a fixed amount that only our server knows, so distances and turns stay right but where you sailed is not shown. Your heart rate is never sent. The other phone shows the data only while the screen is open and does not store it. You can stop sharing or remove a connection at any time.
Share by link. If you agree to it in the app (a separate consent), you can share one item - a session, a speed or a turn - as a link. Anyone who has the link can open a page at slalomsurfing.app without signing in and see that item's share card and numbers, with your name and the day; they can pass the link on. Your heart rate, track, map and positions are never shown. We ask search engines not to list these pages, and we do not log who opens them; the link itself is stored only in a form that cannot be turned back into it. You can take a link back at any time; withdrawing the consent takes all of them back, and deleting the session, withdrawing the session backup or deleting your account makes them stop working.
Finding riders. If you switch on “Riders can find me” (off by default), signed-in riders can find you by name or sail number and see your name, sail number, club and gender.
Spot rankings. Your results appear in a spot's rankings only if you agreed to it in the app. Rankings are visible to every signed-in rider of the app. Without your second consent you are shown as “Anonymous rider”; with it, with the name on your profile, or your sail number if your profile has no name. To check that a session was on the water before it is ranked, our server sends up to 10 points of its track to Mapbox. When another rider passes you in a ranking you get a notification; it names them only if they agreed to show their name, and in the same way a rider you pass sees your name only if you agreed. We keep a tamper-evident record of each consent you give or withdraw.
Challenges. A rider can open a challenge on one value (for example the best 10 seconds or the total distance) for a set time, optionally in an area, for invited connections or open to everyone. When you join a challenge - only with your consent in the app, given once - the other participants, and for an open challenge every signed-in rider who opens it, see your name (or your sail number) and your best value in it with the date of the session it came from. Your track and where you sailed are never shown: our server only checks, from the session summary it already backs up, when a session started, whether it was inside the challenge's area and on the water, and its value. You get notifications when you are invited, when someone passes you, a day before the end and with your final place. Results are kept for 12 months after the challenge ends, then deleted. Leaving a challenge deletes your results in it; withdrawing the consent (Privacy and sharing) takes you out of every challenge and deletes your results.
Comments. Comments you write on a session are stored with your name and shown to the session's owner (and to the riders the owner lets see them). The riders who can see a new comment get a notification with your name and the first 140 characters; it stays in their notification list for up to 90 days, also if the comment is deleted. Anyone who can read a comment can report it: the report, with the comment text and your account id, goes to our problem-report system and our private GitHub repository, where we review it, and is kept there also after the comment or your account is deleted.
Coaching
Coaches and students. Any account can coach, free of charge. A coach finds riders by name or sail number - only riders who have “Coaches can find me” on (on by default; you can switch it off at any time in the app under Privacy and sharing → My coaches) - and sends a request. Nothing is shared until the rider accepts it with a separate coaching consent; a student needs RacePRO and a sail number. A coach is not a connection: your connections do not change.
What a coach sees. Only on the days of the coach's trainings you take part in: the sessions you recorded with our watch app that overlap the training - the real track on the map, every start and turn, your speeds, your name and sail number. A coach never sees your heart rate, your other days or your e-mail address. The results (start timing, mark roundings, the replay) are worked out on the coach's phone each time from the backed-up copies; nothing about you is stored on the coach's side. Every time a coach opens a training we keep a record of which sessions were read.
Ending it. You can end the coaching at any time in the app; the coach then sees nothing of yours and you leave their groups. If you withdraw the coaching consent instead, the coaching is paused, not deleted, until you give it again. Blocking a coach ends it too.
Riders under 18. A student who may be under 18 (we keep only the birth year) also needs a parent's or guardian's consent: we send the guardian an e-mail with a link to a page on our server where they read the coach's profile and this text and agree or decline; the guardian can withdraw it with the same link. We keep the guardian's e-mail address with the coaching and a record of the decision.
Coach profile. A coach fills in a profile (nationality, where they coach, a short text about themselves, and optionally the country they live in, a web link and social media handles); students see it on the coach's requests. With a separate consent the coach can make the profile public: it then appears in the coach search for every signed-in rider, in any country. We never pass messages on - people contact a coach through the coach's own links. A coach can make the profile private again at any time.
Courses and trainings. A coach's groups, trainings, course marks and start times are stored for the coach. A course a coach marks “Other coaches can use it” is shown to coaches nearby; other coaches see only who uses a course and when, never students. When a coach deletes the account, a shared course that another coach still uses is kept without the coach's name.
Free trainings
What it is. A rider with RacePRO can open a free training: a name and a time window of up to 12 hours, and invite up to 30 riders from their accepted connections (the rider who opens it, the lead, is not counted). An invited rider gets a notification and can join or decline; the lead gets a notification about the answer. The training, its members, the buoy positions the lead sets (from the watch or on the map) and its results table are stored on our server until the lead deletes the training or their account; there is no automatic expiry.
What is shared. Only with a separate free training consent, given by every rider who joins and by the lead too (opening a training shares nothing by itself), the lead and the riders who joined see the sessions you recorded inside the training's window: the real track on the map, your speeds and turns, your name and sail number, in a 3D replay and a results table. Only members with RacePRO can open the replay and receive the other riders' raw tracks; members without RacePRO see the results table and a locked preview and never receive those tracks. Your heart rate is removed on our server; your e-mail address and your sessions outside the window are not shared. Your sessions are shared only while you have the current version of the consent, your session backup consent is on and you have SurfingPRO; otherwise the others see you as “session backup off”, “consent missing” or “no SurfingPRO”. Sharing also requires a completed age check and, where needed, guardian consent. If your birth year is missing or guardian approval is pending, your sessions are not shared (“birth year missing”, “waiting for guardian consent”). A block between two riders prevents either rider from receiving the other's sessions or results-table rows. The results table (who rounded each mark first, and the time gaps) is worked out on the lead's phone and stored on our server; on the lead's phone the other riders' tracks are kept in memory only and released within a minute after the screen is left. Every time a member's sessions are read, we record who read whose sessions and when. This read trail is stored in server logs, not in a separate database. Logs rotate by size, with up to ten files of 50 MB each (the oldest first), and are replaced when the server container is recreated. There is no fixed time-based retention period for these logs.
Riders under 18. We ask your birth year once (only the year is kept); an unknown age is never taken as 18 or older. A rider who may be under 18 also needs a parent's or guardian's consent, given once for every free training: the rider gives the guardian's e-mail, we send the guardian a link to a page on our server where they read what is shared and agree or decline, and nothing of the rider is shared until they agree. The guardian can withdraw it with the same link; the rider then leaves every free training and their rows are deleted from the stored results. The guardian's e-mail address is kept with your account until account deletion. We also record the guardian's decision. After account deletion, the consent record is kept for five years without your name, then deleted.
Leaving. You can decline or leave a training at any time on its page. When you leave, or the lead removes you, nobody in it sees your track any more and your rows are deleted from the stored results table at once. Withdrawing the consent (Privacy and sharing) takes you out of every free training and deletes your rows. If the lead withdraws their own consent, the training remains, but the lead's own result rows are deleted and their sessions are no longer shared. If you lose sharing eligibility without leaving, your stored result rows are removed on the next read. Encrypted recovery backups follow the backup retention described above.
Replay videos
When you make a replay video, the app sends the speed and positions of the chosen part (at most 10 minutes, no heart rate) to our server. The server makes the video with a Mapbox satellite image of the area; for that image the track line is sent to Mapbox. The video is deleted when you download it, or after 48 hours. The job record is deleted after 7 days; if making the video failed, the positions stay with the job until then.
Notifications, problem reports, maps and e-mail
Notifications. Every notification (answers, connection requests, shares, comments, ranking changes, your new records and badges) is kept in the notification list in the app for 90 days. Your phone tells our server about your new personal records, badges and finished syncs, so they appear there. If you allow push notifications, your phone's push token is stored with your account. Push messages can contain other riders' names and the start of a comment; they are delivered through Expo (USA) and Apple's or Google's push services. If you set quiet hours, we store them with your time zone. You can turn notifications off in the app or in your phone's settings.
Problem reports and ideas. When you send a report from the app, we store your text, your e-mail address (filled in for you, you can change it), a screenshot of the screen (on by default, you can switch it off for each report), the log of the last watch sync, the app version, platform, language, the screen and a random install id, and, if you are signed in, your account. The screenshot is kept on our server; a copy of the report with your name, e-mail address, account id and a link to the screenshot is kept in a private GitHub repository (GitHub, USA), where we work on it. Reports are kept until you delete your account; the GitHub copy until we delete it.
Maps. Maps are loaded from Mapbox (USA): your phone asks Mapbox for the map tiles of the area shown; Mapbox's own usage telemetry is turned off in the app. Our server also uses Mapbox for the water check and the replay image (above). To name a spot, our server sends the spot's centre point (not your track) to OpenStreetMap Nominatim.
Wind. To show the modelled wind of a session, your phone sends our server the session's place rounded to about 10 km and the hour. Our server asks Open-Meteo for the wind there and keeps the answer per rounded place and hour, without any account id; your phone keeps it with the session. Weather data by Open-Meteo.com (CC BY 4.0).
Country. We keep your account's country, taken from your profile (nationality / sail country) or your phone's time zone — never from your IP address — to see in which countries SlalomSurfing is used.
E-mail. Password-reset e-mails and the e-mails to a student's parent or guardian (see Riders under 18) are sent through Resend.
Photos and share cards. Share cards are made on your phone. A photo you pick as a card background and the cards you save stay on your phone; they are not sent to us. When you share a card or a video, your phone's share menu gives only that image or video to the app you pick (for example Instagram).
Sign-in. If you sign in with Apple or Google, we receive your name and e-mail address (or Apple's private relay address) from them.
When you subscribe
You subscribe in the app through the App Store or Google Play; Apple or Google take the payment, and we never see or store payment details. From the store we receive and keep the purchase itself: which plan, the store's transaction or purchase id, the dates, the status (for example active, trial, renewing, cancelled, refunded) and, in the purchase, our own random id of your account, so the subscription lands on the right account. We use it to unlock the app and your Garmin watch app and to answer support requests. It is kept while your account exists and deleted with it, unless a legal obligation requires us to keep it; the stores keep their own payment records.
This website
No cookies, no analytics, no tracking. The site is hosted by Hetzner in Germany; to count page views, the web server logs only the time, the page and the response of each request, without your IP address or any browser details (user-agent, referrer, cookies). Share links are not logged.
Your rights
You can ask to see, correct or delete your data at any time (KVKK / GDPR) by writing to support@slalomsurfing.app. We never sell your data. Besides the riders who can see what is described above, we use only these service providers: Hetzner (hosting, Germany), Cloudflare R2 (encrypted recovery backups), Apple and Google (in-app purchases, push notifications, sign-in), Expo (push notifications), Polar (only when you connect your account there), COROS (only once that integration is approved and you connect your account there), Mapbox (maps, water check, replay image), OpenStreetMap Nominatim (spot names), Open-Meteo (modelled wind, rounded place and hour only), Resend (e-mail) and GitHub (problem reports).
