New App to export dive data from the Apple Watch Ultra

[OrcasC205]

There has been a lot of talk about the Apple Watch Ultra and how to export diving data from the Oceanic+ and Depth app. I was bored over the holiday since I am still forcibly dry for a couple of months, so I decided to figure out how to solve this problem. After some research and sending my Apple Watch Ultra underwater with a few friends, I learned some things:

1) The Apple Watch appears to be recording underwater depth and water temperature data whenever it is submerged, whether there is a dive application running or not.
2) It is storing those depth and temperature samples in the Apple HealthKit data store independent of whatever dive computer or gauge application is running.
3) It syncs that data with the paired Apple phone's HealthKit data store automatically.

Learning all of this, I plunged headfirst into programming a simple iOS app to export the diving data out of an iPhone into a UDDF (Universal Dive Data Format) XML file so it can be imported into Subsurface or any other dive log application that support UDDF. The app is now available for beta testing through Apple's TestFlight application.

I wrote a quick Getting Started guide that explains what you need to run the app and how to get testing access. It is published at:

AWU2UDDF - Getting Started

There are no guaranties that this will ever make it directly onto the Apple App Store -- the App Review process is fairly stringent, but I will do my best. Please be patient -- this is my first attempt at writing and distributing an iOS app.

 

[Rick Brant]

Nice! Bonus points for doing this while you cannot dive too. Just wondering if the HealthKit data is synced to the desktop automatically. If so maybe Subsurface could parse that data directly.

 

[tmrqs]

Thank you for getting this done!
Would you know if MacDive would be able to open UDDF files?

 

[Chris H]

Thank you for getting this done!
Would you know if MacDive would be able to open UDDF files?

Mac-Dive will import UDDF. I don’t remember if there is a better option or not. Email Nick, and he may be able to have Mac-Dive do a native import from the Apple Watch. This would be done in the desktop version of Mac-Dive.

 

[OrcasC205]

Nice! Bonus points for doing this while you cannot dive too. Just wondering if the HealthKit data is synced to the desktop automatically. If so maybe Subsurface could parse that data directly.

As far as I know, the HealthKit data only syncs with an iPhone, not an iPad or Mac. If your iPhone and Mac share an iCloud account, you can save the UDDF file to iCloud and import directly from Subsurface on the Mac.

 

[Chris H]

As far as I know, the HealthKit data only syncs with an iPhone, not an iPad or Mac. If your iPhone and Mac share an iCloud account, you can save the UDDF file to iCloud and import directly from Subsurface on the Mac.

Yeah, I think you are correct about health data only going to the Watch. I was referring to importing UDDF to Mac-Dive on a desktop version of Mac-Dive. I didn’t mean to highjack your post about a program you developed.

 

[mattfish]

This is fantastic! I took my AWU on a recent trip to coco view resort on Roatan. At the time I could only use the Depth app, since Oceanic+ wasn’t out yet. I had seen the dive data in the Health app, but it’s not very useful in the way it’s presented in there. I’m very interested in seeing what the data looks like in a proper dive log app.

 

[mattfish]

I used @OrcasC205 app to export the dive data from the Health app. I then imported one dive into MacDive and compared what the depth chart looked like compared to the data from my Teric. What I found most interesting is that it looks like there are a lot of measurement points from the AWU data than from the Teric. Overall the data looks very close. The AWU recorded the dive as being 2 minutes shorter than what my Teric recorded. I noticed there were a few "straggler" log entries in the exporter app from the raw data pulled out of Health.app, that I suspect account for the missing minutes. This was probably just while I was at the surface anyway, as it showed a depth of 1-1.4 meters so it was probably just me getting to the ladder after my safety stop. Edit: I realized this was one of my "swim home" dives at CCV where you do a shore return to the resort from the dive boat. So in this case, I was swimming in very shallow water (3-4 feet) for a few minuted to get back to the walk-out point. That is why the dive is a bit shorter on the watch with an extra shallow entry. I must have gotten shallow enough that the watch ended the dive whereas the Teric continued recording. If you look closely at the ends of the graphs you can see the shallow swim to shore cut a bit short on the AWU graph.

Here is a screenshot of the dive data from the AWU (dive number 0) and the same dive from the Teric (dive number 31). Both dives are outlined in red in the dive list.

 

[mattfish]

Now that I uploaded the images, I can see the numbers are a little hard to read, so I'll share that as text here.

Computer	Duration (min)	Max Depth (ft)	Average Depth (ft)
Apple Watch Ultra	36:53	73.02	39.58
Shearwater Teric	38:30	72.60	39.53

 

[OrcasC205]

One thing I should have mentioned is that the Apple Watch Ultra is recording depth and temperature samples every 2-3 seconds compared with about 10 seconds on my Shearwater Perdix, so the profile is a little rougher, for better or for worse, with about four times the data points. I was thinking about putting the AWU samples in 10 second buckets to make it comparable to the Shearwater, but Dirk (the Subsurface maintainer) suggested that some people, like free divers, would appreciate the extra resolution.