A few hours ago, a Reddit user Shamham posted a nice post unique. His brother was on vacation in Zanzibar, where he lost his iPhone. When Search failed to find it, it was found dragging through the Indian Ocean.
Update: A Reddit user himself indicated that the phone was saved by a fisherman, phoned a relative and they were able to return it to its owner.
IPhone protected by airtight bag
Yesterday my brother sailed on an island near Zanzibar and left his iPhone aboard. Somehow, his iPhone crashed into the ship while it was still in the airport at about 11 am.
The author and his family have been following the iPhone track since the beginning. To be an air bag and to be able to transfer its location, the iPhone should be at or near the surface. It all shows that the terminal is pulled by the tide.
As a result, the owner hopes to find it once he gets closer to the beach. Although the long distance has improved by midnight, it is very likely the terminal drains its battery
The Search app lets users track the location of lost devices. From iOS 13, they can rely and other Apple devices nearby which act as a "frequency" of the signal when it runs out of battery. However, since it is a beach with no other users nearby, it will be hard to find.
Of course, it'll be like looking needle smaller than very large grass.