If you are buying an endurance watch this winter, the shortlist is usually the Apple Watch Ultra 3 against Garmin's Enduro 3 and fenix 8. They look like rivals. On paper they are built for different people.
Apple launched the Ultra 3 in September 2025 at $799. Apple rates it at up to 42 hours of normal use and 72 hours in Low Power Mode. For a continuous outdoor workout with GPS, Apple's own figure is 20 hours, and that is in Low Power Mode. That covers a marathon or an Ironman. It does not cover a multi-day race without a charger in your pack.
Garmin's numbers sit in another category. The Enduro 3 lists at $899.99, and Garmin claims 120 hours in GPS-only mode before any solar help, and up to 320 hours with enough sun. With every satellite system in multi-band mode it is about 60 hours, still triple Apple's figure. The fenix 8 with a 47mm AMOLED screen starts at $999 and is rated at 48 hours of GPS and up to 29 days as a smartwatch.
Both track accurately. Apple uses dual-frequency GPS on the Ultra 3, and Garmin uses multi-band GPS. Maps are where they split. Garmin puts full mapping and navigation on the watch itself. Apple supports offline maps with turn-by-turn directions on trails, which is fine for following a route.
Subscriptions are the part people miss. Garmin's core app is free, but Garmin Connect+ launched in March 2025 at $6.99 a month or $69.99 a year for extra charts, AI insights and expanded LiveTrack. The newer fenix 8 Pro adds LTE and satellite messaging, and that needs an inReach plan starting at $7.99 a month. Apple includes emergency SOS, Messages and Find My via satellite free for two years on the Ultra 3.
The case for Apple is everything outside training. It is the better smartwatch by a wide margin, and it only works with an iPhone. For someone who trains a few times a week, it covers endurance well enough, with a charge every day or two.
The case for Garmin is the long stuff: ultras, multi-day hikes, bikepacking, anywhere a charger is a liability. Weeks between charges also means your sleep and recovery data never has gaps.
The short version: if your longest effort is under 20 hours and you carry an iPhone, the Ultra 3 is enough. If you race longer or want weeks between charges, buy the Enduro 3, and skip Connect+ until you know you need it.
