Make a launchpad that holds the bottle with the neck downwards, lets you attach the pump and stand behind the bottle. One good method is to plant a spade or garden fork in the ground at a low angle ...

Water rockets are created from plastic bottles, made aerodynamic by nose cones and fins. The rocket is part filled with water, and air is pumped in with a foot pump.

But now a teacher has gone and ruined all that by making an air-water rocket launching ... The core task is to pump air into the partially filled water bottle and then release it cleanly.

Download the Water ... pops and the bottle flies away. Here's a simpler design using a pump that has a needle for inflating things like rugby or soccer balls. You don't need the bicycle inner ...