Apple Watch Ultra (49 mm, 1st generation) / Samsung Galaxy Watch5 (40 mm, Bluetooth)

LTPO lets the refresh rate drop very low, so the screen can stay on without draining the battery. 2000 nits was twice as bright as any earlier Apple Watch display.

Sapphire crystal is a glass material that strongly resists scratching. The 44 mm version has a 1.4-inch, 450 × 450 screen.

The flat front crystal is protected by a raised titanium edge.

Availability of Ultra Wideband features varies by country.

The L5 signal helps separate signals reflected by tall buildings and trees; Apple called it the most accurate GPS of any Apple Watch at the time.

Availability of the ECG and blood oxygen apps varies by country.

Apple points to the third-party Oceanic+ app for recreational scuba diving to 40 metres; the watch itself is not certified as a dive computer.

The siren plays two distinct patterns, one signalling distress and one mimicking SOS.

With cellular, the watch can make calls and get messages without the phone nearby; carrier support is required.

This version has no LTE; the LTE version is sold separately.

Runtime depends on display, workout and cellular use; using LTE away from the phone drains the battery noticeably faster.

Apple announced that this setting would arrive in software after launch, in autumn 2022; it extends runtime by taking some readings less often.

The watch can only be set up and used with an iPhone; it does not pair with Android phones.

WPC is the body behind the Qi wireless charging standard. The 44 mm version has a 410 mAh battery.

The watch works with phones running Android 8.0 or later with more than 1.5 GB of RAM; it cannot be used with an iPhone.

The electrical heart signal is used for ECG and bioelectrical impedance for body composition estimates; availability of these features varies by country.

5ATM suits shallow-water activities such as swimming, not diving.