I think it is safe to say that Altoid tins can be recycled for further use as handy containers (thereby saving the planet - reducing use of landfills and conserving metal). They serve quite well for that purpose, although some things don't fit well into them. They are a useful component in a thoughtful EDC scheme that will be useful in a lot of tough situations.

They aren't waterproof, per se. If you need to waterproof items, you will have to modify them carefully or go to something else.

Speaking of waterproofing, back in the days when I was scuba diving off the Channel Islands (California) regularly, I played around with the notion of carrying some sort of minimal survival kit that would serve if I ever wound up on an island beach (We almost always dove off of vessels). Dives were routinely down to 60-70 feet and sometimes as deep as 120'. Never came up with a good solution. Any ideas??