A Juice-box-boat!

My friends and I used to have a habit of having ice tea packs when gaming after school. A trashy lifestyle like this also means a lot of trash. By saving up all the drinking cartons over the course of a few weeks, they began to pile up really quickly. Not yet sure with what to do with them, the idea of creating a real boat with them came up. While looking at the pile for the last time, we concluded that this amount of packs could easily support some weight. Which meant we were ready for the design phase!

If you want to do this too, you'll need:

~ 120 drinking cartons

~ 6 rolls of trasparant- or duct tape (150m)

~ a few hours of free time

If you don't have a paddle:

~ an old broomstick or a branch will do the job

And that's it! Note 1: The only costs are basically the tape, and you do not need very expensive tape. So the cost will be about 15 dollars. Note 2: A few more or less drinking cartons will certainly do aswell. This boat was a bit unstable for two persons, or about 120 kg, but really would not sink. Note 3: There are a variety of drinking cartons, drinking milk or water is far more healthy so this would be a very good option as well, it just needs some saving time!

Nice work! You drank some 120L, and have a huge amount of drinking cartons!
This step is a bit overdone at our side, but it is certainly a good habit to think of your building plan before starting the build!

We went for a double layer bottom, and a single layer wall around the boat to block any water from flowing over the bottom. The double bottom wasn't necessary. So this instructable will use only one layer. Because your drinking cartons might be a bit different, it is best to determine the size of the boat with yourself. You would want to sit down with your legs in front of you while in the boat since this is the most stable position. The length of the boat should therefore be about the length of your legs + a bit.

This nice visual design video gives you some idea of the construction.

Since you really need the floating power of the drinking cartons themselves, it is important that they are filled entirely with air. In order to check this, you can gently try to squeeze it. If no air comes out, it is fine!
Otherwise, blow some air in the carton, and make sure the lit is on tightly.

In order to make the bottom section, we will start by creating rows in the length of the boat. We did it a bit differently, but it is much easier to make three rows. In order to do this, you have to lay all cartons side by side until you reach the desired length. Tape the whole row together by going around all the cartons with the tape.

If you finished three rows of drinking cartons, these can be taped together. Lay the rows side by side, and tape the three rows together.

For the sides, you just need two more rows of the same length as the bottom and two shorter rows for the other two sides. If you want to, you can also create a point on one side, to make it look more like a boat. This is however not necessary, a square boat works just as well.

If you managed to create the other rows, you have to tape them on the bottom piece. Make sure to use enough tape on the sides of the cartons! This ensures your boat will be waterproof.

To create a paddle, you have to empty one drinking carton. Make it as flat as you can, and tightly tape it to the branch or broomstick. Make sure the carton is not able to shift, or you might end up with a broken paddle in the middle of the lake.

Finally, you are all set to try it out, and sail away!