Apple Watch Ultra 3 / Samsung Galaxy Watch7 44 mm Bluetooth

Ultra 3 is sold only as a 49 mm GPS + Cellular watch; bands fit 130–210 mm wrists.

Apple says the wide-angle OLED pixels emit light at wider angles, so the screen stays readable without fully turning the wrist. LTPO3 allows thinner borders and lets the always-on mode refresh once per second, so a seconds hand is visible without raising the wrist. The 1-nit minimum reduces glare in the dark.

The 2000-nit peak helps readability in sunlight; using the always-on display shortens battery life.

RedCap is a reduced form of 5G for low-data devices such as watches. Satellite connectivity lets you call for emergency help and send short messages outside cellular coverage; Apple says Find My shares location via satellite every 15 minutes. Satellite services are free for two years from activation; Find My and Messages need a carrier plan, and availability varies by region.

Using L1 and L5 together helps reduce reflected-signal errors near tall buildings and under tree cover. Ultra Wideband availability varies by region.

The electrical heart sensor powers the ECG app; the optical sensor drives heart rate and Apple’s hypertension notifications. Hypertension notifications passively analyse 30-day periods and are not intended for people under 22, during pregnancy or for those already diagnosed. The temperature sensor is not for medical use; the Blood Oxygen app is for wellness use.

Diving needs a compatible third-party app; the depth gauge is accurate to ±1 m. MIL-STD 810H covers altitude, high/low temperature, temperature shock, immersion, freeze/thaw, ice and freezing rain, shock and vibration. Passing these tests does not mean the watch cannot be damaged.

5ATM describes water resistance suitable for surface swimming; it is not for diving or high-speed water sports.

Apple says 15 minutes of charging gives 12 hours of normal use and 5 minutes gives 8 hours of sleep tracking. Apple’s 80% in 45 minutes figure is based on its 20 W USB-C power adapter. Low Power Mode is rated at 20 hours of continuous outdoor workout with full GPS and heart rate.

A fast wireless charging puck is in the box, but no wall adapter.

The siren helps people nearby locate a user who is lost or needs help.

The watch does not pair with Android phones; setup and most features require an iPhone.

The L5 band helps separate signals reflected by tall buildings and trees; dual-frequency mode can increase battery use.

Availability of ECG and blood pressure depends on country and paired phone; blood pressure measurement is not offered in the US.

Energy Score turns sleep, activity and heart data into a daily readiness score; AGEs Index is experimental and not for diagnosis.

This version has no cellular connection; calls and notifications come through the paired phone.