Then we decided to simulate using the Galaxy S7 in the rain. In this case, light drops and sprays of water didn't affect the touchscreen. Once some water had accumulated, however, the touchscreen started misbehaving. And heavier drops falling on its surface were mistaken for taps. Overall, the phone was still usable to some extent, but definitely not once it got too wet.
Our last test was to submerge the Galaxy S7 underwater, which is something you really shouldn't do. The touchscreen in this case was completely unresponsive even though the phone itself still worked. With the camera open, we could take photos using the volume buttons, but the touchscreen itself was not operational.
So obviously, you cannot and shouldn't use the Galaxy S7 underwater, but it is okay to take it out in the rain. Just don't expect its wet touchscreen to be any more responsive than those on any other smartphone, be it water-resistant or not.