Battery Replacement After Dropping Phone in the Ocean
10 - 30 minuten
Our kayak guide kindly offered to take a photo of my wife and I using my wife's iPhone 4s, after which the guide promptly dropped the phone into the ocean. Luckily we were floating over a tidal flat and after about 45 mins of searching and creating a makeshift buoy out of a rock, a water bottle, and some rope we were able to find the phone, mark its location, and go diving for it. Good thing the little silver apple was facing upwards and reflecting the light.
The phone was STILL ON, but acting very wonky (the camera flash was perpetually on, the phone wouldn't unlock). We carefully placed the phone in a bag of rice inside the fridge (so it wouldn't overheat as the light was really starting to warm it up). The phone eventually died and wouldn't respond when plugged in, but we did manage to dry it out enough over the course of a week and prevent too much corrosion. We figured the phone was a lost cause, but there were 1700 photos (not backed up!) still on the logic board, so I had to at least try to recover them.
The battery was easy to replace using the guide. I ended up also using the logic board guide (iPhone 4s) to pull the whole phone apart and clean it up with some rubbing alcohol to remove as much of the salt water corrosion as possible.
After replacing the battery the phone still wouldn't respond when plugged in (it would appear to charge, but wasn't recognized by the computer/itunes (due to some serious corrosion on the connector bus to the logic board)). However, I was able to get the wifi working long enough to install Dropbox and upload all of the photos to my account (and then back them up again to an external hard drive!).
In the end, the phone is a write-off, but the photos have been saved!
If you drop your phone in the ocean, even for as long as 45mins, there is apparently still a chance you can recover your files and photos. It's likely you'll need a new battery, but if you use the very thorough iFixit guides you can clean up the whole phone and give recovery a shot. It's certainly cheaper than a recovery service.
And don't forget - back up your files!