There are studies out currently (I will try to find a copy online and link it) that show that caffeinated beverages are not the evil dehydrator they were once thought to be. These studies done in reference to endurance sports showed that resonable amounts of caffeine (1-2 cups before 3 hours before a workout) actually added in hydration! So, resonable amounts of caffeine will not hurt you in a survival situation...

This study is why you can now find more and more drinks and fuels for endurance sports avalible with caffeine.