Water and Dust Resistance:
Apple Watch SE and Apple Watch Series 9 have a water
resistance rating of 50 meters under ISO standard 22810:2010. This means
that they may be used for shallow-water activities like swimming in a pool
or ocean. Apple Watch SE and Apple Watch Series 9 should
not be used for scuba diving, waterskiing, or other activities involving
high‑velocity water or submersion below shallow depth. Apple Watch
Ultra 2 has a water resistance rating of 100 meters under ISO standard
22810 and may be used for high-speed water sports and recreational scuba
diving (with compatible third-party app from the App Store) to 40 meters.
Should not be used for diving below 40 meters. Water resistance is not a
permanent condition and can diminish over time. For additional information,
Apple Watch Series 9 and Apple Watch Ultra are also
rated IP6X dust resistant.