The Apple Watch Series 12 is A$649 and the Ultra 4 is A$1,349, and you can order both now for Friday 18 September. They look much the same as last year. The change is underneath: a new heart sensor and chip that Apple says makes this the most accurate heart rate reading on any wearable, and a new readiness feature that tells you whether to train or rest.
Both watches share what Apple is calling the Health Sensing System, a new optical and electrical heart sensor pair running on the new S11 chip. Heart rate is now read every five seconds all day, rather than in bursts, and heart rate variability is read up to 24 times more often than before. Apple says it ran a study on more than 1,000 people against other wearables and came out most accurate. That's Apple's study, so treat it as a claim until someone independent checks it.
Readiness
The feature you'll see most is readiness. It takes your recent activity, training load, vitals and sleep and gives you a single number from 0 to 10 each morning with one of four words next to it: Recover, Pace Yourself, Ready, or Go For It. It updates during the day. Garmin, Whoop and Oura have all done a version of this for years, so this is Apple catching up rather than leading, but it's built in rather than a subscription.
There's also a redesigned Health app on the iPhone coming later this year with a Health Age feature. That one launches in US English first, and the blood test ordering that goes with it is US only.
Series 12
Battery is still Apple's usual 24 hours, but outdoor workout tracking goes to 10 hours, up 25 per cent, and 15 minutes on the charger now gets you about 12 hours. Aluminium models get Ceramic Shield 2 on the glass, which Apple says is 60 per cent tougher than the old Ion-X. Sizes are 42mm and 46mm. Aluminium comes in dark bronze, black, light gold and space grey. Titanium in radiant gold and natural. And there's a new ceramic case in pearl white and night blue, which Apple hasn't priced separately in the Australian release, so expect it to sit well above the A$649 starting point.
Ultra 4
The Ultra 4 is where the battery story is. Apple says 50 hours of normal use, 84 hours in low power mode, 25 hours tracking a workout with full GPS and heart rate, and up to 45 hours in the new Max Extended Workout mode. Fifteen minutes on the charger adds about 18 hours. It comes in natural or black titanium. A$1,349.
The AI features, most of which aren't here yet
Both watches get Siri AI with watchOS 27. The more interesting stuff is what Apple calls Audio Intelligence: Live Rewind shows you the last 15 seconds of a conversation as text if you missed something, and Siri Recap writes a summary of a conversation afterwards. Apple says no audio is ever stored, it's processed in a sealed-off part of the chip and deleted, a chime plays when Live Rewind is on, and you opt in to each feature. Both are beta and both arrive later this year, so they're not on the watch you unbox on 18 September. Sound Recognition, which alerts you to sirens, alarms and a baby crying, is the accessibility feature in that group and the one I think matters most.
watchOS 27 is out on Tuesday 15 September for Series 9 or later, SE 3 and Ultra 2 or later, and it needs an iPhone 11 or newer on iOS 27.