The water rocket record
No motors, no igniters, no hazmat. Just a bottle, some water and a bike pump. Water rockets are where a lot of us started, and they go a lot higher than people expect. Put your altimeter in a water rocket, fly it, and if the apogee clears the bar you win points. The first flight to reach 55 metres takes the first win. After that, each new winner has to beat the last winning height by 20%. Beat a 55 m flight and you need 66 m, then just over 79 m, and so on.
About this challenge
No motors, no igniters, no hazmat. Just a bottle, some water and a bike pump. Water rockets are where a lot of us started, and they go a lot higher than people expect.
Put your altimeter in a water rocket, fly it, and if the apogee clears the bar you win points. The first flight to reach 55 metres takes the first win. After that, each new winner has to beat the last winning height by 20%. Beat a 55 m flight and you need 66 m, then just over 79 m, and so on.
What counts
The rocket has to be powered by water and pumped air only. No solid motors and no hybrids. Add a photo of the rocket so we can see what flew.
The height comes from your altimeter's log: the apogee as flown, above the launch pad.
A few pointers
- Use bottles made for fizzy drinks: they're built for pressure. Never use a bottle that's been scratched, dented, heated or glued where it holds pressure.
- Pump from a distance with a long hose or a remote release, and keep everyone well back while it's under pressure.
- Wear eye protection. A bottle that lets go at full pressure is no joke.
- Fit a parachute. Your altimeter has to come back down in one piece, and 50-odd metres is a long way to fall.
- Getting the water and air mix right makes a big difference, so try a few fills and let the altimeter tell you which one works.
Entering your flight
Upload the flight as normal, add the rocket's photo on its flight page, then open the Add my flight tab here and pick it.
Fly safely, and follow the safety code of your club or national association.
How it pays
- First win
- Reach 60.0 m
- After that
- Beat the last winning result by 25%
- Your own result
- Beating it pays again
- Points paid
- Once we have checked the entry
- Dates
- From 5 Nov 2026
Required altimeters
The flight is checked against the altimeter that recorded it
- Hardware
- Rev 4 or later
- Firmware
- 1.65 or later
- Hardware
- Rev 1 or later
- Firmware
- 2.50 or later
- Hardware
- Any revision
- Firmware
- 1.02 or later
- Hardware
- Any revision
- Firmware
- 1.00 or later
Required flight details
Everything is checked when you add a flight- Your own flightFrom an altimeter on your account, and a real flight rather than a test.
- Single stageCounted from the stages of the motors added on the flight page.
- A photo of the rocketAdded on the flight page, or to the rocket the flight is linked to in My Rockets.
- Launch siteSet on the flight page.
- Launch date and timeSet on the flight page.
- Flown during the challengeOn or after 5 Nov 2026.