How the swim data sync process works on Apple Watch:
Your Swim.com swim data is not stored locally on your iPhone once it is transferred away from the Swim.com Apple Watch app, rather it and all of your other account information is stored on and populated to the iOS app from our online server. In order for any swim data to show on your Swim.com iPhone app, your iPhone must have an active data connection to the internet (either via WiFi or cellular data).
Upon ending the recording of a swim, the Swim.com watch app will immediately (and without any prompt to the user), attempt to sync the swim data to our online server. The idea is that it works seamlessly in the background without needing any input from the user, it should basically all just happen automatically without effort.
When the Apple Watch is connected to the internet directly either via WiFi (or with some models via cellular data) and there is no active Bluetooth connection to your iPhone, swim data can be sent directly from the watch app to our online server. This is the fastest and most reliable method of transferring swim data to our server, though not the most widely used method. More frequently, data transmission of completed swims occurs over Bluetooth. This is because, more often than not, our users do not have their watch connected to a WiFi network (or if possible by model - cellular data) while they are at the pool, or if they do, the watch is still connected via Bluetooth to the iPhone. When your watch is connected to both Bluetooth and WiFi, watchOS and iOS work to determine which channel to transmit data between watch and phone and usually this is defaulted to Bluetooth because it takes less battery power to complete this (If you wish to read more about this, please click here: https://support.apple.com/en-us/HT204562)
When swim data is sent over Bluetooth it is not going directly from the watch app to the phone app. After you end the swim and the swim summary is showing on your watch screen, the app is already trying to send the data either directly to our server (over WiFi) or to watchOS where it awaits Bluetooth transfer. WatchOS and iOS then work together to get the data transferred to the iPhone as soon as possible via Bluetooth. This part of the process is something we are unable to alter or change, since it is handled by Apple proprietary technology. Once the swim data reaches iOS/iPhone, the Swim.com app on your phone must be running in the background or foreground in order to retrieve the data and then use your iPhone's data connection to send it to our online server. When it reaches the server, it becomes available to populate on your swim feed on the Swim.com iPhone app.
To refresh your swim feed on the iPhone app, you need to either pull down on the feed itself, toggle between the Progress and Feed tabs, or force quit/close the app and reopen it.
When swims will not sync, there is a series of steps you can perform to try to get the data sent. Please follow these steps in their exact order.
1) Force quit the Swim.com app on the Apple Watch: https://9to5mac.com/2018/09/27/how-to-force-quit-apple-watch-apps/
2) Force quit the Swim.com app on your iPhone: https://support.apple.com/en-us/HT201330
*Force quitting the apps will terminate all running processes originating from the apps so that they start up fresh the next time you open the app.
3) Restart both your phone and watch (this will clear any temporary data caches that could be interfering)
4) When your devices are powered back on, make sure that your phone and watch are communicating/paired via Bluetooth and that your phone has an active data connection to the internet. Additionally, if it's available, please connect your Apple Watch to a WiFi network. https://support.apple.com/en-us/HT209071
5) Once all connections are working properly, open the Swim.com app on your iPhone and then open the Swim.com app on your Apple Watch. Allow both apps to work in the foreground for 2-3 minutes.
6) Refresh the swim feed on your Swim.com iPhone app. This is accomplished by either swiping down on the feed itself, or by toggling between the Progress and Feed tabs.
If those steps do not cause the new swim to populate on your feed, try updating the app in the App Store if there is an update available to you. You can check this on the app itself by going to Settings>About>Check for Update.
If there is no update available, or the update did not solve the problem, try generating a test workout with the Swim.com Apple Watch app. To do this, you do not need to be at a pool. Just start a workout as you normally would and then with the watch-wearing arm, mimic a freestyle stroke until the app shows a completed length for your distance. Once you register a length swam, please end the workout as you normally would. The app should then be trying to sync the test workout and it should push any other available swim data to our server with it. If it syncs the test data but other swims do not appear, please contact firstname.lastname@example.org for instructions on how to navigate your iPhone's files to see if any swim data is "stuck" in iOS and potentially retrievable.
Where issues can occur with data transmission
1) Please refrain from submerging your watch in the minutes after you end the workout. Bluetooth and WiFi cannot transmit through water and submerging the watch can potentially interrupt or corrupt a data transfer.
2) If you leave your phone in the locker room, or in another place where it might be moving in and out of Bluetooth range of your watch, this can also interrupt or corrupt a data transfer over Bluetooth. If this scenario sounds like it might be occurring for you, please disable the Bluetooth connection between the devices while you are swimming. You can do this by either turning on airplane mode on your iPhone or by just disabling Bluetooth. Once you are done swimming and carrying both devices on you, you can re-enable Bluetooth once you are certain your phone will have a solid data connection to the internet.
3) If while you are swimming, your watch and phone remain Bluetooth paired to one another but your phone has a weak or poor connection to the internet, it's possible that after ending the swim the data has arrived at iOS over Bluetooth but encounters an error in the step in which the Swim.com iPhone app is trying to retrieve the data and sync it to our online server through your phone's data connection. This can result in some files being "stuck" on iOS. In some cases we can recover these swims, but only if we can find the data in your iPhone's local file directory. This is avoidable by putting your phone into airplane mode while you are in the pool and not re-enabling connections until you are in a place where you know your phone will have a good data connection.