Here's something that may save lives. While not yet released for purchase, Puri is developing this amazing product that may eventually end up in every ditch bag, or even life raft.
You can read about it here
Simply, put some salt water into the bottle, pump, and the water is pumped into a separate chamber for drinking, leaving the brine water behind to be discarded.
I can't wait to see it available, and the reviews that are sure to come.