If you screw the cap on a milk jug and throw it in the water, it will float. That's because it's full of air. In fact, some people use milk jugs as buoys to help them find boat moorings and anchors. You can use their buoyancy to your advantage.
Imagine you're at a pool or the beach, and you have a young swimmer who hasn't yet grasped the mechanics of swimming. Unfortunately, you couldn't find any floaties or a life jacket when you were packing up. This problem is easily solved if you've got a couple milk jugs lying around. All you need is two milk jugs and some shoelaces or good string. Put the shoelaces or string through the handles of each milk jug and then tie them to your child's arms [source: Owen]. That's it. You've got yourself a set of inexpensive floaties.
Be sure to inspect the milk jugs before you use them to ensure that they're airtight. This is very important! If the jugs have a hole in them, you'll endanger your child. Screw the cap on tight and hold the jug under water. If you see air bubbles coming out, you've got a leak. If not, you're good to go.
If you want to get a little more advanced with your homemade floaties you can always use some Velcro straps or a neoprene brace in place of the shoelaces or string. Either way you'll save yourself some money and an unnecessary trip to the store. Sit back, soak up the sun, and watch your kid splash away.
If swimming's not your thing, the next page offers an idea fit for a weight room.