Apple Watch Ultra 4 - 49mm - Black

It is rated for 100m water resistance, making it suitable for swimming, snorkeling, and recreational scuba diving up to 40 meters.

The battery is designed for multi-day expeditions, though exact life depends on usage settings like GPS and always-on display configurations.

Yes, bands designed for the 42mm, 44mm, and 45mm cases are generally compatible with the 49mm case.

Yes, the Apple Watch Ultra 4 uses on-device processing for many Siri requests and audio tasks to ensure privacy and functionality in remote areas.

The Health Sensing System uses advanced optical sensors to take frequent measurements throughout the day and night to calculate your HRV trends.

Yes, it includes built-in satellite communication features for emergency connectivity when cellular and Wi-Fi networks are unavailable.

Ensure both devices have Bluetooth enabled and are updated to the latest OS versions. Restart both the iPhone and the Apple Watch.

Ensure you are in an open area away from tall buildings or dense tree cover during initial calibration, and check that location services are set to 'Always' for workout apps.

The watch requires approximately 3-5 days of consistent sleep and activity data to generate an initial baseline for the Readiness Score.