The Apple Watch Ultra is built to survive outdoors adventures, but you'll want to forget about repairing it yourself if you take a tumble. iFixit has completed a video teardown indicating that the Ultra isn't significantly more repairable than its regular counterparts. While there are external screws on the back, you're going to wreck a waterproofing gasket if you pry the rear open. And don't even think of getting through the front — it's difficult to avoid breaking the screen, at least without special tools.
It's also tricky to access the battery and other components. The teardown also illustrates just how much larger the speaker array is on the Apple Watch Ultra compared to the Series 8. Even if you're unlikely to ever use the siren feature those speakers are meant for, it should help with call quality and other audio-driven apps.
This isn't the advancement in fix-it-yourself friendliness you saw in the base iPhone 14, then. You'll need to take this to a pro repair shop if you land badly during a hike. Even so, iFixit is optimistic the Watch Ultra represents a path toward more repairable Apple wristwear. While it's not clear if future smartwatches will make that leap, it won't be shocking given mounting political pressure on the tech industry to create more easily maintained devices.