Occasionally my wife and I buy bottled water in bulk for our son to drink in the car or at the park on hot days. It is convenient for making sure that he, and we, stay hydrated. But it can be a hassle to have a bunch of bottles rolling all over the car or smashing things in a bag. So I had some paracord lying around and put it to work keeping things together.
Step 1: The Knot
The running knot is simply an overhand knot with the working end pulled through to form and adjustable loop. This is the knot that is used to bind the bottles together.
Step 2: Bottle Number 1
Once you have the first knot tied, slip it over the bottle cap down below the lip on the neck of the bottle.
I used ordinary water bottles, 8 oz size, but any size water bottle or other bottle with a pronounced lip around the neck would work. Using the same size bottles allows the 'pack' to sit together on a flat surface neatly, though using bottles of different sizes is still possible.
Step 3: Adding Bottles
After the first knot is attached to bottle 1, make another in the working end of the cord and put it on the second bottle, always being careful to leave the working end to the side of the knot farthest from the first bottle. All the knots should look the same from the top as well so that they will sit/hang together well.
Step 4: Results
These will sit together well and hang from just about anything you can think of with no problem. When removing bottles they don't need to be removed in any particular order since the weight is always tightening each knot around the neck of the bottle it is holding.
There you have it, an easy way to keep water bottles together and portable.