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Science Rocks!

Survival Raft


your results

Sent in by:
Jessica of Oceanside, CA

Make a raft that will float your boat, and some potatoes....

Materials Needed

  • 2 pieces of plywood
  • balloons
  • garbage bags
  • duct tape
  • scissors
  • bubble wrap
  • Styrofoam cups
  • 2 gallon jugs of water
  • 5 pounds of anything (the ZOOMers used a sack of potatoes)
  • an inflatable wading pool filled 2/3 with water



  1. Check with a grown-up before you get started. This is an activity you'll need to test in water outside in warm weather.
  2. Imagine that you're stranded on a deserted island. A raft would be a really handy survival tool, either to help you get off the island or to move supplies around.
  3. See if you can build a raft that will hold 2 gallons of water and 5 pounds of supplies (a total of about 21 pounds.)
  4. Use materials like balloons, garbage bags, bubble wrap, Styrofoam cups and plywood. Remember that the raft needs to be strong enough to hold all your supplies, but also light enough to float.
  5. Test your survival raft in the "ocean" of an inflatable wading pool.

Here's the sci scoop on what floats your boat: When the raft is put in the water, it starts to sink, pushing water out of the way. It's kind of like it makes a hole in the water. The raft stops sinking when the weight of the water it pushes out of the way is equal to the weight of the raft and everything on it. If, when your raft stops sinking down into the water, some of the raft is still above the surface of the water, that means your raft floats. Try building a raft that holds your weight. Or build a smaller raft that holds your soap and sponge while taking a bath. Be sure to send your ideas and raft results to ZOOM!

Some of your Results

Roadcran, age 11 of Canton, CT wrote:
I used it in my pool and trust me I would deffinatly recommend it to anyone stuck in the wild.. don't worry w/ this u'll stay afloat!!

Nichelle, age 11 of Sacramento, CA wrote:
When I got on it didn't sink! I guess because I made it where it couldn't sink.

Alexis, age 7 wrote:
It tipped but we stayed in the raft.

Samantha, age 10 of Easton, MD wrote:
First I put my nephew on it and it stayed. But when I got on with him it sunk! I got wet. I used two trashbags and Strofoam cups.

Chris, age 15 of Round Rock, TX wrote:
It floated for 12 seconds then sank.

Cody, age 11 of Champaign, IL wrote:
It held me and my supplies. It worked perfectly.

Kurt, age 15 of Houston, TX wrote:
Mine floated in our swimming pool in the backyard. It didn't last very long because it was starting to sink in a minute.

Jake, age 6 of Los Angeles, CA wrote:
Remember when you made that raft out of tape and balloons and cups and wood? Well, you could just put some cups and balloons on the back and use it as a boogie board (without the balloons on the outside corners).

Milosz, age 10 of Schiller Park, IL wrote:
When I tried my raft for the sponge and the soap I realized that the wind from the window blew my raft to the opposite direction not where I wanted it to be, what I mean by that is the wind could blow the raft back to the island so, maybe you should bould something like an engine or a mast.

Jordan, age 9 of Bardonia, NY wrote:
I did it in a real pool and mine half flooted it sank half way.

Shelby, age 10 of Grayson, KY wrote:
It worked for exactly 2 minutes. I figured out why it sunk. I had put 2 huge sgaures of styrofoam on the bottom. One came off so it tilted to one side. I tried again and made sure it wouldn't fall off. I got on and put all my supplies on it. It still sank! I guess I should use small potatoes next time!

Melissa, age 15 of Westerville, OH wrote:
Well I was smart and used styrofoam and cut it and tied it together using string I floated in my neighbors pull but when my bro and me tryed to get on it tipped over. O well we were already wet.

Ashley, age 11 of Lindon, UT wrote:
Well, I used it it the bath tub to hold my shampoo it held up okay. It sunk a little bit.

Elizabeth, age 9 of Houston, TX wrote:
It floated when I was on it, but it sank when my brother was on it.

Brianna of Corpus Christi, TX wrote:
It worked pretty good it held up to 10 pounds I used wood and strings.

Michael, age 13 of Toronto, ON wrote:
Even though this is new and it hasn't been brodcasted, I think it's cool. I used 2 different materials to test. Cardboad worked better than paper. My brother thought it was cool so he wants to watch the premiere.

Kelli, age 10 of New Bedford, MA wrote:
I floated my baby sister on my raft, and it stayed, but when I got on, we sunk, and I got wet!

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