Product Price Heart Rate Monitor GPS Waterproof Rating (IPX) Battery Life (hours) Screen Size (inches) Activity Tracking
Garmin Garmin Fenix 8 (Sapphire Solar 51 mm)
US
£899.46 10 ATM up to 48 days (with solar) 1.4 in / 35.5 mm multi-sport activity profiles, step counting, sleep, VO2max, training load, recovery

The Garmin Fenix 8 Sapphire Solar 51 mm is a rugged multisport GPS smartwatch with solar charging, a high-accuracy multi-band GNSS receiver, and an optical wrist heart rate sensor. It offers extensive activity tracking and dive-rated water resistance, designed for long outdoor use with very long battery life when exposed to sunlight.

★ Ideal for

Ideal for durable outdoor use because it has a 10 ATM water rating, multi-band GNSS for reliable tracking, and up to 48 days battery life with solar charging.

Garmin Garmin Enduro 3
US
£674.59 10 ATM up to 120 hours GPS-only; up to 320 hours with solar; up to 36 days smartwatch mode 1.4 in running, trail running, hiking, cycling, swimming, multisport, sleep, VO2 max, training load, recovery, HRV metrics

The Enduro 3 is an ultraperformance GPS smartwatch built for very long outings with an MIP display, solar-charging ring, titanium bezel and sapphire lens, and extensive navigation and training features. It combines multi-band GNSS, long battery life and robust activity/health tracking to support multi-day adventures and endurance athletes. It is aimed at users who need durable hardware and exceptional battery life for extended outdoor use.

★ Ideal for

Best for durable outdoor fitness use because it has a 10 ATM rating, titanium/sapphire build, multi-band GNSS and an optical HR sensor plus up to 120 hours GPS battery life (320 hours with solar).

Polar Polar Grit X2 Pro
US
£749.55 WR100 Performance training mode: 43 h; Eco training mode: 140 h; Smartwatch mode: 10 d 1.39 in 24/7 activity tracking, step count, sleep tracking, SpO2, skin temperature, ECG, recovery metrics

Premium rugged multisport watch with a sapphire-protected 1.39 in AMOLED display, dual-frequency GPS, advanced Polar Elixir biosensing (optical HR, wrist ECG, SpO2, skin temp), MIL-STD-810H durability and long battery modes for multi-day use. Suited for outdoor athletes who need accurate navigation, comprehensive physiological metrics, and a durable build.

★ Ideal for

Ideal for outdoor activities because it combines dual-frequency GPS for accurate positioning, MIL-STD-810H durability and WR100 water resistance, plus up to 43 hours GPS battery life in performance mode.

Amazfit Amazfit T-Rex Ultra 2
US
£412.25 10 ATM (supports dives to 45 m) Up to 30 days (typical use) 1.5 in AMOLED 180+ sports modes with advanced running metrics and dive modes

The Amazfit T‑Rex Ultra 2 is a rugged 51mm titanium outdoor smartwatch with a 1.5 in sapphire AMOLED display, dual‑band GPS, an improved PPG heart rate sensor, 10 ATM water resistance with 45 m dive support, and up to 30 days battery life. It includes offline full‑color maps, a two‑color flashlight, 64 GB storage, and 180+ sports modes for extensive outdoor and training tracking.

★ Ideal for

Ideal for durable outdoor fitness tracking because it has a Grade 5 titanium build, dual‑band GPS, 10 ATM water resistance with 45 m dive certification, and up to 30 days battery life.

Suunto Suunto 9 Peak Pro
US
£186.64 100 m Up to 40 hours (GPS), Up to 21 days (daily use) null 115+ sport modes; step counter; calories; sleep tracking; activity history

Suunto 9 Peak Pro is a thin, military-tested multisport GPS watch with sapphire glass and durable materials, offering accurate GPS navigation, wrist-based heart rate, long battery life up to 40 hours in GPS mode and extensive activity and sleep tracking. It includes dedicated snorkel mode, navigation features and over 115 sport modes, suited for athletes and outdoor adventurers who need reliable navigation and long runtime.

★ Ideal for

Ideal for durable outdoor activity tracking because it is tested to military standards, rated waterproof to 100 m, has sapphire glass/titanium or stainless steel construction and up to 40 hours GPS battery life.