Apple's iPhone 7 isn't officially classified as a waterproof. With its IP67 rating it is capable of surviving immersion at a depth of one meter (3.3 feet) for 30 minutes but this is meant to protect against accidental drops into water or splashes rather than make the phone suitable for underwater activities.
However, an incident during an ice fishing trip in Russia has now demonstrated that the device offers more environmental protection than its IP rating would suggest. According to Russian language publication ykt.ru a fisherman dropped his iPhone 7 Plus into an ice fishing hole in the city of Yakutsk. Unable to retrieve the device, it was left in the water overnight, until the next day a diver friend of the phone's owner was, after three attempts, able to find the device and bring it back to the surface.
When taken out of the water, the iPhone powered on successfully and did not show any signs of malfunction after 13 hours in the freezing 4°C/39°F water. According to its owner the iPhone 7 Plus had approximately 35 percent battery charge when dropped and still showed 19% after the successful retrieval, which is documented in the Instagram video above. It's great to know the iPhone is likely to survive even longer periods of time submerged in water, but we'd still recommend dedicated underwater equipment for your next diving or snorkeling video.