The feature uses new gyroscope and accelerometer sensors — the kinds used in dash cams to save footage in an accident — to detect front-, side- and rear-impact collisions, as well as rollovers.
It will immediately call emergency services, send your location and alert your emergency contacts.
Apple Watch Series 8 also features multiple temperature sensors for advanced health tracking, detecting issues with sleep, jetlag and retrospective ovulation settings.
Temperature can be read to changes of as small as 0.1 degrees, allowing for alerts around variations in cycle estimates, something that could be an indicator of bigger health issues.
Watches from the Series 4 up to those announced today will get a new low-power mode to ensure up to 35 hours of battery life by turning off the always-on display and automatic workout detection.
Apple Watch Ultra targets hardcore fitness enthusiasts
The biggest headline for Apple Watch today though is the new Apple Watch Ultra.
While it looks a lot like an Apple Watch, it’s completely redesigned with a larger, stronger titanium case, with additional sensors and speakers.
There’s an all-new action button designed directly for the adventure and sports types who need advanced features like compass, tracking and diving capabilities.
Apple Watch Ultra has a flat screen within the 49mm case, the largest Apple Watch yet.
This new watch is a big leap forward for Apple, taking on rugged sports watch bands like Garmin and Suunto, which are the choice of hikers, adventurers and long-form athletes like triathletes.
Apple Watch Series 8 will be on sale in Australia from September 16, and will be priced from $629
A new Apple Watch SE hits at the same time for $399.
The all-new Apple Watch Ultra will be on sale September 23 and will be priced at $1299.
Trevor Long travelled as a guest of Apple Australia.