FoneFox have tried to test the Apple Watch and see if it can survive under various submersion tests. The Apple Watch has IPX7 water-resistant under IEC standard 60529 (its IP code). So according to the IP code specs, the Apple Watch should be able to continue functioning after immersion up to 1m in fresh water for 30 minutes.
That said, Apple does not recommend does not recommend submerging the watch as it, and I quote: “.. Apple Watch is splash and water-resistant but not waterproof”. So you can it’s safe against rain and when washing your hands, but other than that, you should keep your watch in a dry environment.
As you can see from this video by FoneFox, the Apple Watch survived 15 minutes inside a swimming pool and continued to function without any issues. They did report that the screen was less responsive underwater because of its capacitive screen, but once they took it out of the water, it went back functioning properly again.
So again, if you try to swim with it or submerge the Apple Watch in water for a long period of time, you risk damaging it. If I had the Apple Watch, I probably wouldn’t dare taking that risk and go for a swim with it. I can understand that people want to have their watch on their hands without remembering to take it off when going to the shower or going for a swim at the beach.
That being said, you can now maybe feel a bit more secure, knowing that even if you enter water with it by mistake, you’ll still have time notice it and remove it from your wrist and put it somewhere safe.