The problem is that water is an excellent RF attenuator. Even if the phone was working, it would be useless even under a few metres of water. For this reason su

The problem is that water is an excellent RF attenuator. Even if the phone was working, it would be useless even under a few metres of water. For this reason submarine communication is only one way and requires kilometre long ELF emitters (which everyone in the world can pick up). Above 20m depth you can use VLF, but it's still only one way. The second problem is that phone location relies on there being a cell tower nearby (or a few so you can triangulate). You don't get a good reception in the middle of the Pacific, I'm guessing. Not to mention the third problem that we're told to put our phones into airplane mode anyway. Even if the phones had WiFi or Bluetooth on, it's a higher frequency than GSM and has an even poorer range underwater.