I flooded my GoPro Hero3 Black Edition last Sunday. I was filming blue and mako sharks at the surface via a long pole from the boat deck. Shot off and on for several hours before I noticed it had turned off. When I inspected it, I notice the housing was full of salt water. While I can say that several sharks did grab onto the housing, the housing was still shut and there are no signs of visible damage on the housing. The o-rings look good and I can recreate the flooding at home. Not sure why it flooded unless show how it partially opened when a shark grabbed it, but sealed itself again once it was let go?
On a positive note, I was able to save the camera. Although I had limited resources for several hours still being on the boat, I simply pulled the battery and memory card and stuck everything in the zip lock bag containing my spare GoPro Anti-Fog inserts. Once we got back to shore, I immediately went to the closest grocery store and bough a package of rice and zip lock bags. I placed everything again into the zip lock bag filled with rice.
When I got back home 2 days later, I tried to power it on. The red light flashed on and off and I could hear an electronic sound from the unit, but no luck. Since it had been flooded with sea water and it wasn't powering on a few days later, I decided to take more drastic measures. I took the entire GoPro apart (pulled the front cover off and removed the four screws allowing me to pull the inside apart from its plastic case). I then dunked all the parts (electronics and all) into a bowl of white vinegar to stop the corrosive process from the salt water. I swished the vinegar around for about 15 seconds. Then I quickly air dried the GoPro and stuck everything back into a bag of rice for another 5 days. Today I opened the bag, removed any residual rice from the GoPro, reassembled it, inserted a fresh battery, and it powered on
I've tested it shooting video and it worked. Since I'm not an electronics expert and can't assure this will work for you, try at your own risk. However, if all else fails, I'd give this a shot before you throw it away.
Taking the GoPro out again for another day of sharks, so we'll see how it does long term.