Hmm. So theoretically it would last a session kiting by itself in a backpack, but for longevity the case might be an idea. $250 is a lot of money for a case, even if $1000 isn't a lot of money for a camera.
I wonder if a couple of shopping bags and some rubber bands might work instead?

There wouldn't be an issue if a few drops of water got inside because the unit is still waterproof, but it might drastically reduce the effects of long term saltwater exposure. The more I think about it the more I like it. I'm going to try it and see how much water gets inside the bags before I go dropping five pineapples at it.