Apple Watch Ultra should not be employed for diving down below 40 meters. Drinking water resistance is not a everlasting condition and might diminish after a while. For extra information see assist.apple.com/HT205000. However, when it comes to sleep patterns, the Oura Ring has an edge around the Apple Watch, https://deanqfteo.develop-blog.com/38976509/considerations-to-know-about-aura-ring-finger