The $799 (£849, AU$1,299) Apple Watch Ultra is bigger and more rugged, but at its heart it has much of the same functionality and health sensors as the $389 (£419, AU$629) Apple Watch Series 8.

The Apple Watch Ultra has the usual assortment of Apple Watch features introduced on the Apple Watch Series 8, including the new body temperature sensor. All well and good.

Pre-order, release date, pricing — Apple Watch Ultra pre-orders start today at $799. The rugged smartwatch comes out on September 23. Apple Watch Series 8 ...

Fitness tracking and heart monitoring are well and good — any smartwatch hitting the market now is expected to have these features. Still, the Apple Watch Ultra goes a few extra miles by ...