When Apple launched its Apple Watch Ultra in September, the company said the new, rugged wearable will be a fully-fledged diving computer, but the Oceanic+ app that enables that functionality was scheduled to launch at a later date.

Now, the day has come: The Oceanic+ app, designed by Huish Outdoors together with Apple, is available in Apple's App Store.

Apple says that the Watch Ultra, together with Oceanic+, is aimed at recreational scuba divers, which in practice means diving up to 40 meters (130 feet) of depth. The Ultra has water temperature and depth sensors, but the app is what enables divers to set up and monitor all the parameters they need for a safe dive. This includes a dive planner, where users can set surface time, depth, and gas, with the app calculating the no-decompression time, which tells the diver how long they can stay at a certain depth.

Other features include dive conditions (such as tide and water temperature data, as well as information on visibility and currents), GPS-enabled entry and exit locations, depth graphs, and other goodies that divers might find useful. The app also brings new factors into play, allowing users to integrate info such as no-fly time, surface time, as well as access to the dive planner or dive settings, to their preferred watch face.

The larger size of the 49mm Watch Ultra, compared to the regular Apple Watch (which only goes to 45mm), as well as enhanced brightness (up to 2,000 nits), should help divers see all the info they need while underwater. The Watch Ultra also provides haptic feedback, which Apple says will work even through a 7mm-thick wetsuit.

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The Oceanic+ app works only with the Apple Watch Ultra running watchOS 9.1, paired with an iPhone 8 or later, or the second generation iPhone SE or later, running iOS 16.1. The free version of the app offers functions such as depth and time, and logging recent dives; for more advanced functionality, including decompression tracking, tissue loading, location planner, and an unlimited logbook, users will have to pay $9.99 per month or $79.99 per year.