A pro diver’s thoughts on the Apple Watch Ultra dive computer

Photo by Clément Lauwaert on Unsplash

I’m an Apple kid for life. I grew up in the San Francisco Bay Area as Apple did: the first iPhone came out when I was in high school. I’ve had Apple products for as long as I can remember. Currently, I own an iPhone, 2 MacBooks (1 for work, 1 personal), an iPad, and yes, an Apple Watch.

I also dive for a living — I’m a marine biologist and scientific diver and do about 200–300 working dives a year.

So when it was announced that the new Apple Watch Ultra would be a fully functional dive computer, that certainly caught my attention. But I knew pretty quickly it was not the computer for me, and I’m here to tell you why.


Target Diver

First and foremost, we need to remember that the Apple Watch Ultra isn’t designed for every diver. The target audience is people who already own an Apple Watch, who go on a dive vacation once or twice a year to recreational depths. People who will be upset but ultimately fine if their watch gets flooded. For that person, I can see the appeal. Plus there’s the Apple “cool factor” that I have to admit I’m fully bought in to.

The Apple Watch Ultra is not a computer for a dive professional. It’s not hardy enough to survive all the stresses, bumps, and scratches that a daily-use dive computer endures.

But even for a once-a-year recreational diver, I have some concerns.


If you read the fine print, it says waterproofing is not guaranteed over time. This sounds to me like right about when your Apple Care is up, you might not want to take it underwater anymore.

The fine print also says the Watch is water resistant to 100m, but that doesn’t mean you should take it there. (I’ll be getting my 100m certification soon, someone send me an Ultra and I’ll test it out!)


Every dive computer uses an algorithm to calculate how much time you can spend at the current depth without needing to complete extra stops on your way up. In theory, it protects you from getting the bends. But the algorithm is just a model. It’s not reading the amount of nitrogen in your blood. It’s calculating how much nitrogen it thinks is in your various tissues, and how much it thinks your body can handle. And as anyone in the hurricane belt knows, models can be very wrong.

The Oceanic algorithm is pretty liberal, allowing you to stay deeper, longer than most other dive computers, which is potentially dangerous for newer divers. That said, it’s good that Apple is going with an established algorithm and not making up their own. On the other hand, the Oceanic+ app is also a new product. It will be released with the watch. In theory, it’s the same as Oceanic’s full-service dive computers, but that remains to be seen.

Note that the app is an additional charge, as it requires a subscription.

Battery Life

I’m worried about the battery life of the Ultra. It promises up to 36 hours but I frequently can’t get through 24 hours with my current watch. Logging exercise makes the battery deplete faster, even when the display isn’t on the whole time. It seems that during a dive, where it is providing continuous lighted display and logging data, the battery would drain pretty quickly. Could you do two or three hour-long dives in a day with it?

I also wonder how functional the Ultra battery would be in cold water. Luckily, the target audience probably isn’t doing much of that, instead opting for a week in Cozumel or Belize, as many people do. Apple does claim the Ultra will function well in extreme temperatures, but I have to imagine that long exposure to cold water will make the battery last for less time.

Screen Visibility

There is definitely a market for dive computers with large, bright screens, for divers with aging eyes. The Apple Watch will never be able to provide that, because of their devotion to looking cool, even though the Ultra will have the brightest screen yet.

Photo by Bobbi Wu on Unsplash

Possible Future Upsides

All that said, there are some promising possibilities as the technology develops.

Fitness Tracking

There’s a lot of buzz around the dive industry about heart rate tracking and other biometric capabilities for dive computers. Apple, with its strength in fitness tracking, could help speed this along.

Health monitoring within a dive computer is promising for improved safety. A diver can look at their watch and see their heart rate is too high, encouraging them to stop exerting and just breathe for a minute. Maybe it could even alert their buddy to a cardiac event. Hopefully the buddy is paying attention and notices, but when you can’t speak underwater there could be confusion about what is going on.


Could we also maybe get diver-to-diver communication through watches? A selection from a small set of preselected messages could be rapid and useful. For example, “I need help” (not urgent), “emergency” (urgent), “time to go up”, or “I used half my tank” are situations in which there are hand signals a diver can use, but if their buddy’s back is turned and they can’t hear an audible signal (we bang a metal clip on our tank), maybe their watch could get their attention.

Closing My Rings

Warning: mini-rant in this section. If you don’t own an Apple Watch, you probably won’t enjoy it. You can skip to the next one, I won’t be offended. But if you are also annoyed by the constant reminders to move, please, commiserate with me.

There is another, very petty, esoteric reason I’d like to bring my Apple Watch underwater. Right now, I don’t bring my Apple Watch on dive days. It’s too much of a hassle to switch between my Apple and dive watches before and after every dive. So when I get home and put it back on, usually around 6 or 7 pm, the rest of the evening I get shamed by my watch that I wasn’t active enough that day. It buzzes a few times to tell me I need to stand, or get up and go for a walk, because “You can do it!”. Because I wasn’t active enough that day. In reality, I was much more active than in a normal day, moving tanks around, swimming, and standing for most of the day. I would have crushed my rings if I could wear the Watch the whole time. And my watch is yelling at me, because it has no idea. So being able to bring the Watch and have it know that I’m diving might get it to shut up.

Mini rant over. Sorry, this happens to me about 3 days a week and it’s really annoying. But I put the watch on in the evening because I like to wear it when I sleep.

Photo by Adrien Delforge on Unsplash


Regardless of the potential future developments, as it is right now, the Apple Watch Ultra is not the dive computer for me. I regularly go beyond 130’ on repetitive dives, which is not what this is designed for. It’s going to take a lot to convince me to use anything but Shearwater.

Good on Apple for going for a large market with a small amount of effort. But I don’t think that, as a headline on the topic stated, “Suunto should be terrified.” Although they might lose some of their market share, an Apple Watch is not the same product. Smart divers (such as this one) always dive with a backup, so they will still be purchasing regular dive computers in addition to the Apple Watch.

Ultimately, you are trusting your life to this device, and this is Apple’s first model. It may work great for you as a vacation diver. Just be aware of its possible limitations, and be safe.

You might also like these posts:

I Did a Staycation. Here’s How You Can Do One Better

4 Reasons To Try Scuba Diving If You Haven’t Before

What An Earthquake Feels Like From Underwater