It's one of the iPhone 7's biggest selling point.

Apples highly anticipated iPhone 7 was released on Friday after a lot of rumours and teasers about how it would differ from previous iPhones. While Apple bragged that its camera was better and its battery would last longer, people were very intrigued about whether it was really as water-resistant as the company claimed it to be. Several tech people have taken to youtube to showcase the new phone and its features but one man who runs a channel called EverythingApplePro went to extreme measures to see if it was really water-proof. According to Apple phone users can immerse it in 1 metre of water and leave it there for 30 minutes and it will be perfectly fine. "But will it really hold up? that's what I want to find out" He says. The man in the video makes a metre long tube in which he puts the phone for over 30 minutes, when it comes out, it's perfectly fine. "I'm liking this'' he says. He then went to a lake where he jump of 15 feet and swam around for a bit. He then jumps in a few more times, just for good measure. And the phone was perfectly fine.

"The iPhone 7  is much much more capable than you guys think in the water" I'm actually very surprised, Apple seems to have underrated it Not only did it survive for 30 minutes in the water it also survived all the jumps and jolts in the river." He says.

https://www.youtube.com/watch?v=lYEeb4U6ZYs So maybe don't leave it immersed in water over night or anything, but if you drop it down the toilet it looks like it'll be okay!