So.... They all say you will flood a housing eventually. And I laughed. HAH! ME? never.... right? Nope. It actually has happened to me three times. All human error. Fortunately two of the times it was so little water that there was no damage. The last time though cost me a camera, a lens, and battery. I managed to save the memory card though. The camera took one last image before I hopped in the water. I have since replaced it with a 7d. :)
Just remember, attention to detail, it's a photographer, and well, any other professional's bread and butter.
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The last photo of a trusty and reliable canon 50d.
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The damage salt water causes is permanent. Lens still has salt and moisture inside, battery is corroded, and the camera body is full of salt deposits and corrosion.