Apple Watch Ultra 3 / Amazfit Bip 6

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.

2000 nits is the peak only, used briefly to improve readability in sunlight.

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.

The PPG sensor tracks blood flow under the skin with light to measure heart rate, blood-oxygen saturation and heart-rate variability during sleep. These readings are not for medical diagnosis.

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.

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.

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 standard 22 mm strap width lets third-party straps be fitted.

According to Amazfit the watch withstands the pressure of 50 metres of still water for up to 10 minutes; there are pool and open-water swimming modes.

A full charge takes 1.5–2.5 hours. The box includes a magnetic charging head but no USB-C cable; any USB-C cable can be used.

Built-in GPS lets runs and rides be recorded without the phone; turn-by-turn direction prompts are supported.

Calls go through the phone over Bluetooth; the watch has no cellular link or Wi-Fi. Third-party music apps cannot be installed, but music playing on the phone can be controlled.

Chest-strap heart-rate monitors, running and cycling power meters and cycling speed/cadence sensors can be paired. Data can be exported to apps such as Strava, komoot, Google Fit and Apple Health; there is no sync with Samsung Health or MyFitnessPal.

The Zepp Flow voice assistant works only in selected countries and regions.