Oceanic+ app on Apple Watch Ultra below 40 meters?

[alex-vasenin]

Even though Apple Watch Ultra rated as 100m water resistant its depth sensor seems to be limited to 40 meters, as Apple say:

Your Apple Watch Ultra is designed to comply with EN13319. The Depth app works to a maximum depth of 130 feet (40 meters). If you go below this depth, the screen turns yellow, and some functions of your Apple Watch Ultra might stop working or might work intermittently. The depth sensor on Apple Watch Ultra is accurate to plus or minus 1 meter.

Apple Watch Ultra and its depth sensor are compatible with third-party apps that can serve as a dive computer for recreational scuba diving to 130 feet (40 meters).

I wonder, what exactly would happen with Oceanic+ app if one go below 40 meters? Did anyone try it already?

 

[jborg]

Yes, many people, search for the threads here. In short, it doesn’t work below 44m, and then it locks out.

 

[Belzelbub]

Yes, many people, search for the threads here. In short, it doesn’t work below 44m, and then it locks out.

Yep. Since the data pulled from HealthKit doesn’t record anything below 44M, it appears to be an Apple limitation, not Oceanic+. Not sure if that’s a hardware limitation or a firmware decision. But unless that limitation is addressed, I would expect any other dive apps for the AW Ultra to behave the same.

 

[Eric802]

I think the consensus was that it’s a hardware limitation.

 

[Belzelbub]

I think the consensus was that it’s a hardware limitation.

I’m not sure it’s hardware. The line seems far too consistent to be a hardware/sensor limitation. Hardware would have variations. Looks more like a coding decision than a sensor limitation.

Reminds me of the torque curve on my truck. It climbed quickly, then was flat for the rest of the rpm range. Turns out it was an ECM program that capped the torque well below what the engine was actually capable of.

 

[cheinelt]

I’ve done such a „dive“ as a simulation of such a dive to see what it does. 44m is the maximum. The simulation was done with a tester to test if watches are really water proof down to 70m.

 

[kimh]

"What happens when you dive too deep with the Apple Watch Ultra? I put it to the test to show you exactly how the Apple Watch Ultra 'Depth' app works, as well as how the data works behind the scenes. Dive on in!"

>> Apple Watch Ultra pressure test (YouTube)

 

[kimh]

Still learning this discussion software. Looks like you can't delete a comment- originally this was to be just a test comment to see how attaching an image worked. It's a screen shot from the Apple Watch Ultra pressure chamber test video - linked in the previous comment.

 

[kimh]

I think the consensus was that it’s a hardware limitation.

I’m not sure it’s hardware. The line seems far too consistent to be a hardware/sensor limitation. […] Looks more like a coding decision than a sensor limitation.

I don't think it's hardware either. My understanding is that Apple chose a software cut-off (for now) that corresponds exactly to the generally agreed upon depth-limit for recreational diving. No doubt they're concerned about liability, and about their public image; in case of watch-related accidents. Actually I'm surprised that they did this diving stuff at all. The whole Apple Watch Ultra thing seems like an uncharacteristically aggressive product choice for them. They're really going after Garmin and other smart watch/sports vendors.

This is the main reason I expect Apple to extend the depth limits later, via software. They're too cautious to start this project with tech diving capability, which is a tiny niche, after all. After the watch develops a solid track record, I expect them to increment its functionality.

 

[jborg]

Obviously the cutoff is in software, what we can't know is if it's due only to liability concerns or actual hardware limitations.

My guess is that it's both, and that it's not going to change in this hardware revision. That is, once they decided that 40m was enough, the smart thing to do is find the cheapest sensor that covers that range with whatever margin for safety is required. Then you code the cutoff to stay within the sensor recommended range. Done and done, decision locked in for this hardware iteration.

There's a huge difference between an actual dive computer, where the depth sensor is the foremost primary concern, and the Apple watch where it's a minor technical afterthought and ideally should take up as few cubic micrometers as possible and cost as little as possible.

If the AWU takes off big time as a dive computer there might be a business case for a better sensor in a future hardware revision and the decision might be reconsidered. I'm not holding my breath, given the size of the target audience.