Apple Watch Ultra 4 First Look

*First look based on manufacturer specifications and published reports. Hands-on review to follow.*

Plenty of divers already wear a smartwatch to the dive shop. The question is whether it can stay on the wrist when the boat reaches the site. Apple's answer, now in its fourth generation, is the Apple Watch Ultra 4. Apple announced it on 10 September 2026, and it went on sale in Australian stores on 18 September. Apple says it is certified to EN13319 for recreational scuba diving to 40 m, and with the Oceanic+ app it works as a full dive computer.

The target buyer is the recreational diver who already lives on an iPhone and wants one device for training, travel and the occasional reef dive, not a dedicated dive computer that sits in a drawer between trips. That covers a large share of Australians who dive a handful of times a year, whether on a Cairns day boat or a summer shore dive at Shelly Beach. Technical divers and anyone planning dives past 40 m are not the audience, and Apple says so plainly.

Dive Certification and Depth

The Ultra 4 has a water resistance rating of 100 m under ISO 22810:2010. That figure gets quoted a lot, but it describes how well the case resists water, not how deep the watch can dive. The number that matters is EN13319 certification for recreational scuba diving to 40 m, with depth accuracy of plus or minus 1 m. Apple says it should not be used below 40 m. That matches the 40 m limit for recreational diving, so a Deep Diver course fits within it but anything beyond does not.

A depth gauge and a water temperature sensor are built in, and Apple lists automatic launch at 1 m along with GPS entry and exit points. MacObserver reports that the water rating, dive certification and depth gauge are unchanged from the Ultra 3. For divers, this generation is a refinement, not a new instrument.

Oceanic+ and Dive Computer Functions

On its own, the watch shows depth, time and water temperature. The dive computer comes from Oceanic+, an app from Huish Outdoors, and Apple notes that a subscription is required. According to the developer's App Store listing, Oceanic+ uses the Bühlmann algorithm and includes a no-deco planner where the diver sets gas mix, maximum depth and dive time. Underwater it shows depth, time and ascent rate, with visual and haptic warnings.

Version 4.0.1, released in April 2026, added multi-gas management for up to three tanks, each with its own mix, maximum operating depth and a ppO2 setting from 1.4 to 1.6. Version 4.1.1, released on 25 September 2026, merges dives recorded on the watch, an iPhone and up to two dive computers into a single log. The app offers scuba, freediving and snorkelling modes on the Ultra, and dives are logged with GPS location, photos and video, which suits divers who like a tidy digital logbook after a liveaboard week. Apple's own advice is worth repeating: dive with a companion and carry a secondary device.

Display, Build and Wearability

The 49 mm case is Grade 5 titanium, and Apple says it is 3D-printed from 100 per cent recycled titanium. The Always-On Retina display sits under flat sapphire crystal and peaks at 3,000 nits, which should help in bright tropical shallows as well as in the murk of a winter dive in Sydney Harbour. The watch measures 49 x 44 x 12 mm and weighs about 63 g, though larger dedicated computers usually show bigger numbers. Apple has also moved the Ocean Band to a translucent silicone, offered in grey, kelp and black.

Battery, Charging and Safety

Apple rates battery life at up to 50 hours of normal use, up to 84 hours in Low Power Mode, and up to 45 hours of Max Extended Workout tracking. Apple says 15 minutes of charging adds up to 18 hours of normal use, which is useful between morning and afternoon dives. Apple doesn't publish a dive-specific battery figure, so how many dives a charge covers on a five-day liveaboard remains to be seen.

Emergency SOS and Find My via satellite are included free for two years. For divers this is a surface feature, not an underwater one, but it is relevant for remote shore dives with no mobile coverage.

Key Specifications

| Specification | Detail | |---|---| | Dive certification | EN13319, recreational scuba to 40 m (plus or minus 1 m accuracy) | | Water resistance | 100 m (ISO 22810:2010) | | Dive software | Oceanic+ (subscription required), Bühlmann algorithm | | Sensors (dive relevant) | Depth gauge, water temperature, compass | | Case | 49 x 44 x 12 mm, Grade 5 titanium (natural or black) | | Display | Always-On Retina, flat sapphire crystal, up to 3,000 nits | | Weight | 63.0 g (natural), 63.1 g (black) | | Battery | Up to 50 hours normal use; up to 84 hours Low Power Mode | | Fast charge | 15 minutes for up to 18 hours of normal use | | Chip | S11 | | Satellite | Emergency SOS and Find My (free for two years) | | Price (AU) | From A$1,349 RRP inc. GST | | On sale in Australia | 18 September 2026 |

Drawbacks

- Hard 40 m ceiling. The certification stops at 40 m and Apple says not to go below it. Divers working towards technical training will outgrow it. - The dive computer is a subscription. Full Oceanic+ functions need an ongoing plan on top of the A$1,349 watch, unlike a dedicated computer that is paid for once. - No published dive battery figure. Daily-use figures are generous, but Apple doesn't say how long the watch lasts in dive mode, which matters on multi-day liveaboards. - Wireless air integration isn't listed. Neither Apple's specifications nor the Oceanic+ description mention wireless tank pressure, which competitors such as the Garmin Descent Mk3i offer. - Little new for divers. Published reports say the dive hardware is unchanged from the Ultra 3, so Ultra 3 owners gain nothing underwater by upgrading.

Verdict

For the recreational diver who already uses an iPhone and dives a few times a year, the Ultra 4 makes a strong case on paper: a certified 40 m instrument with a bright display, the Bühlmann algorithm through Oceanic+ and a battery that handles daily life without fuss. Australian pricing has also dropped A$50 against its predecessor, according to Finder. Regular divers who want air integration, a published dive-mode battery figure or no subscription should skip it, and it is the wrong tool for anyone heading past 40 m. Those divers should look at the Garmin Descent Mk3i or the Shearwater Teric.

Sources

- Apple Australia: Apple unveils Apple Watch Ultra 4 (10 Sep 2026) - Apple Australia: Apple Watch Ultra 4 technical specifications - App Store (AU): Oceanic+ by Huish Outdoors - Finder: Apple Watch Series 12 and Ultra 4 price and availability in Australia - MacObserver: Apple Watch Ultra 4 for scuba and snorkelling