You are right that water storage is important and worthwhile to carry in a kit, even if it is redundant. <br><br>I can't give any specific advice on using a mylar baloon. It was just an idea someone suggested. I don't think that person had even tested it out yet. It would be the standard baloon that you would get at a drug store filled with helium with "Happy Birthday" on it. They can also be purchased uninflated for 2 or 3 dollars each.<br><br>They are sturdy (relatively speaking), compact and light. I think they would be easier to fill than a condom because they wouldn't require as much positive pressure to expand the container. It's easy to fill a condom from a faucett, but try filling it from water standing in a sink basin, and you will see what I am talking about. Of course the mylar baloon would be a bit tricky, too. I haven't tried it. If you are willing to do some experimenting, this is just a suggestion for one area to look at.<br><br>Good Luck.<br><br>