The latest Samsung flagships – the Galaxy S7 and Galaxy S7 edge – are both beautiful and waterproof with IP68 certification. And both have their microUSB port exposed, which is something only Sony did before.
It turns out Samsung has installed an additional failsafe on the USB port to prevent water damage. It’s called moisture detection, and it won’t allow you to charge the phone until the charging port is dry.
If you pull the Galaxy S7 or S7 edge out of the water, you won’t be able to charge it right away. Users report a message about moisture detected in the charging slot. It may take an hour, or even a few hours for the port to dry up, and until then you won’t be able to charge your phone. This is very thoughtful otherwise, there is a chance you may end up killing your phone.
There is this one user that reported his Galaxy S7 couldn’t fast charge after his USB port was usable again post water submersion, which sounds bad. Normal charging was OK, but fast charging was impossible – there’s no way to confirm if that’s an actual bug at this point though.
And while we are on the pool subject, you may find this video about Galaxy S7 edge pool test rather enjoyable.
Thank you, Jason, for the tip!
Source 1 (XDA) Source 2