Apple Watch Ultra (49 mm, 1st generation) / Samsung Galaxy Watch5 Pro 45 mm

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 resists scratches better than mineral and aluminosilicate glass; the raised bezel around the screen protects the glass from knocks.

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.

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.

The D-Buckle band uses a folding clasp so the strap sits at the same point every time, in place of a standard pin buckle.

Samsung says the battery is 60% larger than the Galaxy Watch4’s.

Wear OS 3 and later do not work with iPhone. Blood pressure and ECG work only in markets supported by Samsung Health Monitor and with Galaxy phones.

Bioelectrical impedance analysis estimates values such as body fat and skeletal muscle; results are not for medical diagnosis.

Track Back follows the recorded path in reverse to help you return to the start.

5ATM covers surface water activities such as swimming, not diving or high-pressure water. MIL-STD-810H is a set of military test methods, not a guarantee of impact resistance.