Apple Watch Ultra 3 as a Dive Computer: The Complete Oceanic+ Guide

Apple Watch Ultra is the first mass-market smartwatch that can legitimately work as a recreational dive computer. That's a big deal for divers who already wear one every day. It's also a source of real confusion. The watch alone isn't a dive computer. The app you add makes it one. And the combination has hard limits that matter for your safety and for whether it fits the way you dive.

This guide covers the Apple Watch Ultra 3 with the Oceanic+ app: what it does, where it stops, what it costs to run, and who should, and shouldn't, rely on it.

How Apple Watch Ultra became a dive computer

When Apple launched the original Apple Watch Ultra in 2022, it added a depth gauge and water temperature sensor, and certified the watch to EN13319. That's the European standard for diving accessories like depth gauges and dive computers. A few months later, Huish Outdoors, the company behind the Oceanic dive brand, released Oceanic+ for the Ultra. The app turned the watch into a full recreational dive computer, and it was designed in collaboration with Apple.

The Ultra 2 followed in 2023. The Ultra 3 arrived in late 2025, keeping the titanium case, sapphire front crystal, and large, very bright display that make the Ultra line readable underwater. From a diving perspective, the core formula hasn't changed across generations: the same recreational depth range, the same reliance on a third-party app for decompression calculations, and the same lack of tank-pressure integration.

The Depth app vs Oceanic+: know the difference

Every Ultra ships with Apple's built-in Depth app. It shows time, current depth, maximum depth, and water temperature. It's fine for snorkeling or shallow water sports. But Apple is explicit that the Depth app is not a scuba dive computer. It doesn't track nitrogen loading, no-decompression limits, ascent rates, or safety stops.

For scuba, you need a third-party dive app. Oceanic+ is the best-known and most established option. Others have appeared since, including apps from DIVEROUT, Mares, and Diving Standard. They differ in price, logbook features, and extras, but all run within the same 40 m hardware limit.

What Oceanic+ does underwater

Oceanic+ runs a Bühlmann decompression algorithm, the same family of algorithms used by many dedicated dive computers. You can adjust its conservatism before a dive. Underwater, it tracks:

• Depth, dive time, and water temperature
• Your no-decompression limit
• Ascent rate
• Safety stops

Warnings arrive as color-coded visuals plus haptic taps on your wrist, which many divers find more noticeable than beeps from a traditional computer.

A few practical details stand out:

• It launches automatically when submerged. You can also map it to the Ultra's Action button for a one-press start.
• The touchscreen doesn't work underwater. You navigate with the Digital Crown and physical buttons, which are designed to be usable with gloves.
• Surface GPS marks entry and exit points. That's handy for logging shore dives and finding them again.
• The iPhone companion app handles dive planning, the detailed logbook, and community-shared site information.

The hard limits

1. 40 meters (130 feet) maximum

Apple rates the Ultra for recreational scuba to 40 m / 130 ft, and says compatible dive apps can function to that depth. That's the recreational diving limit taught by major training agencies, so for most divers it isn't restrictive.

What happens beyond it matters, though. The watch isn't designed to provide dive data below 40 m. Divers on forums report that depth data stops being recorded not far past that point, leaving you without a computer. Don't plan dives that approach the limit with the Ultra as your only instrument. Our depth ratings explainer covers why a "40 m rating" and "100 m water resistance" mean completely different things.

2. No air integration

Oceanic+ on the Ultra has no wireless tank transmitter support. You can't see remaining gas on your wrist, so you'll still need a submersible pressure gauge (SPG) on your regulator or a separate air-integrated computer. If air integration matters to you, compare the dedicated options in our air integration transmitter guide.

3. Recreational, not technical

The Ultra and Oceanic+ are built for recreational no-decompression diving on air and nitrox. It doesn't support trimix, multiple gas switches for technical dives, or closed-circuit rebreathers. Technical divers should look at purpose-built computers.

4. Battery life is a smartwatch's battery life

This is the biggest practical difference from a dedicated dive computer. The Ultra has good battery life for a smartwatch, but it's still a smartwatch. It runs GPS, a bright display, and everyday apps on one charge. Reviewers consistently report that dive-mode endurance is well below what dedicated computers and dive-first watches like the Suunto Ocean deliver.

On a liveaboard doing four or five dives a day, you'll be charging every night at minimum. Build charging into your routine, and never start a dive day on a partial charge.

5. Water resistance isn't permanent

Apple notes that water resistance can diminish over time. Drops, impacts, heat, and chemicals can all compromise seals. A dedicated dive computer is built around its pressure housing. A smartwatch is a phone-grade device built to be tough. Treat it accordingly: rinse after salt water, avoid hot tubs and saunas, and get damage checked.

The subscription model

Oceanic+ basic features are available without paying, but the full dive computer requires a subscription. Oceanic has offered annual, monthly, and short-term day-pass options. Day passes suit someone who dives only on an occasional vacation. Annual plans suit regular divers.

One subscription covers your personal devices:

• Apple Watch Ultra: scuba and freediving to 40 m.
• Apple Watch Series 10 and later: snorkeling to 6 m (20 ft).
• iPhone in the Oceanic+ Dive Housing: diving to 60 m (196 ft), with photo and video capture.

We don't list prices because they change. Check the Oceanic+ listing in the App Store for current plans in your region.

Freediving and snorkeling

Oceanic+ includes a freedive mode on the Ultra, also limited to 40 m. It offers customizable depth and time alarms delivered as haptics, plus surface interval tracking. For recreational freedivers and snorkelers, it's a genuinely good tool, and the everyday heart-rate and training data carries over to dry apnea sessions.

For deeper competitive freediving, the 40 m ceiling becomes a real limit. See our best freediving watches for dedicated options.

Who the Ultra 3 suits

• iPhone users who dive a few times a year. One device for daily life and vacation diving, with no extra computer to pack or forget.
• Newer recreational divers staying within Open Water and Advanced depth limits, who like a clear, colorful interface.
• Snorkelers and recreational freedivers who want depth and time tracking with wrist alerts.
• Divers who want a backup. Some experienced divers wear an Ultra alongside a dedicated computer as a secondary instrument.

Who should look elsewhere

• Android users. Oceanic+ requires Apple hardware.
• Divers who want air integration. Look at the Suunto Ocean or Garmin's air-integrated models.
• Technical divers using trimix, multiple deco gases, or rebreathers.
• Heavy dive-trip divers doing many dives a day who don't want daily charging anxiety.
• Anyone who wants to own the computer outright rather than subscribe.

Alternatives worth comparing

Accessories that make the Ultra better for diving

Pre-dive checklist for Apple Watch Ultra divers

1. Charge fully. Start every dive day on a full charge. Carry a charger and cable on the boat.
2. Update before the trip, not during it. Install watchOS and Oceanic+ updates at home, then confirm everything works. Our {link('update-dive-computer-firmware','firmware update guide')} explains why timing matters.
3. Check your subscription. Confirm it's active before you lose connectivity at a remote dive site.
4. Set gas, conservatism, and alarms. Configure your nitrox mix and conservatism setting before the dive, and set depth and time alarms.
5. Test auto-launch. Confirm Oceanic+ is set to launch on submersion, or map it to the Action button.
6. Carry backups. Bring an SPG for gas, and ideally a secondary depth gauge and timer.
7. Rinse after salt water. Fresh water rinse after every dive day, and keep it out of hot tubs.

Oceanic+ vs other Apple Watch dive apps

Oceanic+ was first, but it's no longer the only option. As of mid-2026, the main alternatives include DIVEROUT, a Mares app, and Diving Standard. All run within the same 40 m hardware limit, and hobby comparisons note that they commonly use Bühlmann-based algorithms. Where they differ:

• Price model: some are subscriptions, and at least one offers a free tier.
• Logbook and planning depth: some have full iPhone companion apps; others run mostly on the watch.
• Extras: photo color correction, sea-condition data, and community features vary.
• Maturity: Oceanic+ comes from an established dive-computer brand and has the longest track record on the platform.

Whichever app you choose, check its current feature list, gas support, and reviews. Then learn it thoroughly in the pool or on easy dives before relying on it.

What a dive actually looks like on the Ultra

On a typical boat dive, you'd start by confirming your gas and conservatism settings in Oceanic+ during the ride out. When you enter the water and descend, the app launches automatically and begins tracking. Depth, dive time, NDL, and water temperature sit on the main screen. Turning the Digital Crown pages through additional data, like the compass.

If you ascend too fast, the watch warns you with color and haptics. At the end of the dive, it guides your safety stop with a countdown. Back on the boat, the dive syncs to your iPhone logbook with a GPS-tagged entry point, which is great for remembering shore-dive sites.

The bottom line

The Apple Watch Ultra 3 with Oceanic+ is a legitimate recreational dive computer. For iPhone owners who dive occasionally, it's hard to beat the convenience of one device on your wrist. It is not a replacement for a dedicated computer if you need air integration, technical gases, all-day dive battery, or depths beyond 40 m. Know the limits, carry a backup, and it'll serve you well.