Here’s to a healthy life.
Apple Watch Series 1 requires an iPhone 5s or later with iOS 11 or later.
Apple Watch Series 3 has a water resistance rating of 50 metres under ISO standard 22810:2010. This means that it may be used for shallow-water activities like swimming in a pool or the ocean. However, Apple Watch Series 3 should not be used for scuba diving or waterskiing, or other activities involving high-velocity water or submersion below a shallow depth.