It is highly impractical to take your phone into the ocean or pool to keep track of time. This watch is waterproof for up to 600 feet or 20 atmospheres. It was issued by Swatch over 30 years ago. It is only available on the secondary market and is sought after by collectors. This watch and its strap are in very good gently used condition. It is used and sold without warranty. I have observed it and it keeps the accurate time and is in fine kit.