Do ships currently have a method to preserve important documents in case of a shipwreck?

Alright - I need help with a wacky, random, out-of-the-blue issue I've been struggling with. I'm currently writing a sci-fi/horror story about two explorers travelling down into the challenger deep (deepest part of the Mariana Trench with 16,000 pounds of water pressure per square inch). The story takes... show more Alright - I need help with a wacky, random, out-of-the-blue issue I've been struggling with. I'm currently writing a sci-fi/horror story about two explorers travelling down into the challenger deep (deepest part of the Mariana Trench with 16,000 pounds of water pressure per square inch). The story takes place in the year 2267, while the ship sank today, in 2017. To make matters worse, the ship has had a large radiation leak (I don't know if that would have any effect on the papers), and there's a massive colony of decomposer bacteria and algae that would be able to eat it if they got access to it. There probably isn't a feasible solution that would be likely to actually happen, but is there any way to somehow make the papers NOT destroyed and LEGIBLE so that my characters can get information about the shipwreck?

I'll be happy to consider any ideas you consider, even if they involve using things other than paper. My issue with things like waterproof electronics, however, is their limited battery life. The salt in the water would also corrode the metal of the electronics, and eventually water would probably break its way inside because of the massive pressure.

I know these are probably the worst possible conditions for trying to preserve something, but I thought I'd ask anyways. If you need more details on other things, let me know and I'll get back to you when I can!

Thanks,
~ Brandon
6 answers 6