The Oceanic Plus app gets some big updates for both versions of the Apple Watch Ultra. The Apple Watch Ultra 2 has plenty of features for fitness enthusiasts. But divers in particular get two exclusive features: Apple's own Depth app and Oceanic Plus from Huish Outdoors that turns your Apple Watch Ultra into a dive computer.Both the original Apple Watch Ultra and Ultra 2 get new features for free diving and improvements to the overall dive experience with Oceanic Plus 2.0. Free diving is a specific type of diving without using a tank, instead relying on the diver to hold their breath for an extended period of time. The app has a free version, but requires a $10 monthly subscription to unlock the free diving features, photo editing tools and more comprehensive dive computer tools. My CNET colleague Jesse Orrall tested the first Oceanic Plus app with the Apple Watch Ultra in Catalina, California, and found it a helpful dive tool, albeit with some limitations.There's a new stealth mode that dims the screen by 90% when you free dive, so you don't disturb marine life. It also silences all alarms and any haptic feedback from the app. There's also a new option in free diving mode to set custom alarms for metrics like target depth and maximum dive time.When you surface, the app will also display heart rate, heart-rate training zones and calculate recovery time. Apple Watch Ultra compared to the dive computer built into my regulator.For other dives, the app has notable improvements including a new weight planner that can help calculate the right amount of ballast (or weight) you need. The app can also help you plan more easily with real-time water temperatures and conditions as reported by other Watch wearers. It also shows a three-day forecast. This is information you'd normally get from a local dive store.The app also supports the Oceanic Plus Dive Housing, a $490 case to protect the iPhone underwater. You can use it to take photos and videos, or turn your iPhone into a dive computer with the same data as what appears on the Apple Watch Ultra and Ultra 2. Apple's own Depth app, which is separate to Oceanic Plus, launches automatically when Apple Watch Ultra models are submerged in water. You can also launch it using the Action button. Now, the app temporarily stores a log of your session on the watch for seven days, with a permanent version saved to the Fitness app on iPhone.