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Water Rocket Derby

Bottom line is you can google just about anything, and get cub scout water rocket instructions. Do remember that you can put an egg (we will supply the eggs) in your rocket and if it returns to earth uncracked you get a 5 second bonus. So as you construct your rocket determine if you want to have a "cargo bay" to store an egg or not. You do not have to launch your rockets with the egg, it is optional.

A Rocket has 6 basic parts:

  1. Fuel Area - For us that is an empty 2 Liter Soda Bottle.
  2. Cargo Bay - If you want to Launch “something” (egg), then cut the top and bottom off of another  2-Liter Soda Bottle and tape it to your Fuel Area.
  3. Nose Cone - This is where your Parachute goes.  Cut the top off of a third 2-Liter Soda Bottle. Place it on the top of the Fuel Area (or Cargo Bay, if you have one). DO NOT tape it down. Add Weight to the very tip of you nose cone…Why? (Watch out for Newton’s Law about inertia)
  4. Parachute - Cut a large circle out of a plastic trash bag. Put tape on the edge where you want to attach the guide strings. The parachute must return ALL rocket parts!
  5. Fins - Fins help the Rocket go straight. Tape 3 or 4 Fins to the bottom of your Fuel Area
  6. Fuel - We will use water and pressurized air to propel our rockets into the sky!

 Derby Rules 

  • No Metal Parts!
  • Air Pressure will be the same for everyone. 
  • The boys pick how much water they want to put in. (about ¼ full works best). 
  • Judges will time the flights.
  • Flight Time will start at launch and ends when  any part  of your rocket returns to earth.
  • Returning an UNCRACKED Passenger (egg) adds 5 seconds to your flight time. 

We STRONGLY recommend that you use a Coke or Pepsi bottles. Off brand bottles tend to fit on the launcher awkwardly and don't launch as well at times.

For a really detailed view on the steps you can head out to YouTube, this one in particular is very step by step, but this person takes their water rockets VERY seriously. You don't need to do half of what is done in this video to make it work. But, these are the best in terms of seeing step by step instructions. There are 6 videos, linked below:
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