My wife and I just got back from a ten day trip to both Texas and Florida. Before leaving, I opened my suitcase to pack and found a couple of space bags I had completely forgotten about.
If you’re not familiar with the space bag, it’s basically a giant zip-lock bag with a one-way air release valve on the side of the bag. What you do is: Put your clothes inside the bag, zip it closed, and then roll the bag forward to squeeze the air out of the bag. In the process, all of your clothes compress down to approximately 1/3 of their original size.
So, not only does the space bag save space in your suitcase (or bug out bag) but it also keeps it relatively dry, should your bag happen to get wet. “Relatively” dry meaning: Mostly dry. Since there is still a valve on the side of the bag where air can escape, I’d imagine that (theoretically) water could somehow get in, although it would be unlikely. Still, much better than simply folding your clothes and putting it in your bag without any protection, whatsoever.
I don’t know why it never occurred to me before to use a space bag for the clothes in my bug out bag. Sometimes the obvious hits you when you least expect it.