How to Use the Depth App on Apple Watch Ultra to Track Underwater Dives

Recreational water sports—such as snorkelling, freediving, spear fishing, and swimming pool workouts—require precise tracking of underwater depth and immersion time. Historically, tracking these underwater parameters required bulky, dedicated dive computers. With the Apple Watch Ultra series (Ultra and Ultra 2), Apple engineered an EN13319-certified depth gauge capable of measuring underwater depths down to 40 metres (130 feet) alongside water temperature sensors.

To deliver an intuitive underwater experience, watchOS includes the native Depth app. Designed for high visibility beneath the surface, the Depth app can automatically engage as soon as you submerge into water, displaying real-time depth readings, maximum depth reached during the session, elapsed underwater duration, and water temperature in bold, high-contrast numbers.

Key Metrics Displayed by the Depth App

When underwater, the Depth app screen presents four critical telemetry indicators designed for effortless glancing through a diving mask:

• Current Depth: Prominently displayed in large, bold numbers at the top of the watch face (in metres or feet).
• Maximum Depth: Records the deepest point reached during the current dive immersion cycle.
• Water Temperature: Measures the ambient temperature of the water around your wrist in real time.
• Time Underwater: Tracks the elapsed immersion duration down to the second, starting from the moment you descend past 1 metre (3 feet).

Configuring the Depth App to Launch Automatically

The most convenient way to use the Depth app is to let Apple Watch Ultra detect water submersion automatically so you do not need to press buttons while wearing swim gloves:

1. Press the Digital Crown on your Apple Watch Ultra to open the app grid.
2. Open the Settings app.
3. Scroll down and tap General.
4. Select Auto-Launch.
5. Under the When Submerged section, locate Auto-Launch App.
6. Tap Auto-Launch App and select Depth.

Now, whenever your Apple Watch Ultra is submerged to a depth of 1 metre or more, the watch’s Water Lock engages automatically to prevent accidental touchscreen input, and the Depth app launches instantly on your display.

Customising the Depth App via the iPhone Watch App

You can also configure default measurement units and behaviour from your paired iPhone:

1. Open the Watch app on your iPhone.
2. Select the My Watch tab from the bottom navigation bar.
3. Scroll down through your installed apps and tap Depth.
4. Choose your preferred Depth Units (Metres or Feet).
5. Choose your preferred Temperature Units (Celsius or Fahrenheit).

Mapping the Action Button to the Depth App

If you prefer initiating your underwater session manually before leaping off a boat or dock, map the physical orange Action Button directly to the Depth utility:

1. Open Settings on your Apple Watch Ultra.
2. Tap Action Button.
3. Under Action, select Dive.
4. Under App, select Depth.

Pressing the Action Button will now launch the Depth app and engage Water Lock immediately, ensuring your watch face is primed before entering the water.

Exiting the Water and Reviewing Your Session

When you finish your snorkelling or diving session and surface above water:

1. The Depth app automatically transitions to a Session Summary screen showing:
   • Total time spent underwater.
   • Maximum depth achieved.
   • Minimum water temperature recorded.
2. Because Water Lock is active to prevent droplet false touches, press and hold the Digital Crown for two seconds.
3. A sequence of sound tones plays to eject water droplets from the speaker cavities, and the touchscreen unlocks.
4. Tap Done on the Depth screen to conclude the session.

Reviewing Dive Telemetry in Apple Health and Fitness

All dive data captured by the Depth app is logged automatically to your Apple Health repository on your iPhone:

1. Open the Fitness app on your iPhone.
2. Under the Workouts / Sessions category, tap your recorded Diving or Water Activity session.
3. Tap Show More to reveal a detailed depth profile chart showing your ascent and descent rates, depth fluctuations over time, and water temperature telemetry.

Important Safety Guidelines and Limitations

While the Apple Watch Ultra and native Depth app are certified to the EN13319 standard for recreational water immersion, proper safety protocols must be observed:

Activity	Depth App Suitability	Operational Recommendation
Snorkelling & Free Diving	Fully supported up to 40m (130ft).	Ideal for monitoring breath-hold duration and water temperatures.
Scuba Diving	Basic depth gauge only (Does not compute decompression limits).	For scuba diving with no-decompression limits (NDL) and gas mixes, use a dedicated scuba app like Oceanic+ alongside secondary backup dive computers.
High-Speed Watersports	Water resistance rated up to 100m.	Suitable for wakeboarding, surfing, and kitesurfing.

By configuring the native Depth app on Apple Watch Ultra, you turn your smartwatch into a reliable underwater companion that tracks aquatic fitness effortlessly.