Class A Water Rocket Competition Rules

I.      Water Rocket General Class ‘A’ World Record Design Parameters

1)   Rocket must reach record altitude using a single stage. Multiple Stage Water Rockets compete in the WRA2 Class B.

2)   Rocket must use Water as its primary reaction mass.

3)   Water Rocket must use compressed ambient atmospheric air as its energy. Other gasses have much higher compression ratios and there needs to be a baseline so the record is fair to all. (see section II for special rules regarding bottled air).

4)   Pressure Vessel and Fuselage of Rocket must be constructed from lightweight nonmetallic materials.

5)   Rocket must be launched from a stationary position on a fixed launcher. (Slingshots, trebuchets, catapults, cannons, and all other forms of launcher boost assist are forbidden). Launch tubes are allowed as long as the internal pressure of the rocket is the only supply of energy.

6)   Rocket must be completely scratch-built using materials which are not manufactured for model rocket parts. (with the exception of the Camera and Altimeter) Raiding hobby shops for nosecones, or fins, or any other pre-manufactured items is prohibited.

7)   Rocket must carry onboard a commercially produced recording ("Logging") altimeter to document the entire flight on a Time vs. Altitude Graph to nonvolatile logging memory or telemetry to relay the altitude information to a remote logging receiver. Ground based and/or timing based altitude measurements are too error prone and are unacceptable.

      So-called "Peak Altitude" altimeters are also unacceptable because they are subject to false peak readings caused by external factors such as:

           · Recovery system deployment.
           · Landing impact.
           · Improper installation.
           · Unstable flight characteristics.

8)   Flight must be recorded by ground-based video to validate flight duration and recovery. It is required proof the flight actually happened. (if using bottled air is used then the 10 minute max pressure hold must be shown)

9)   Entire flight including apogee must be photographed by an onboard video camera.

10)  Record Altitude is calculated as the average of the two highest flights the rocket achieves within a 2-hour period. This prevents dumb luck, the “perfect storm” scenario or false readings from giving a false record. Results must be repeatable!

This criteria was inspired by high profile competitions such as the Ansari X-Prize.

11)  The same rocket must be used for all averaged flights. The only portions of the rocket which can be replaced are expendable or consumable items. (batteries, tape, deployment chemicals, water, etc..) The same rocket must be used for all attempts. Items which are damaged in any record attempt must be repaired and reused. Any competing rocket must be sturdy enough to survive multiple launches and the recovery system must be robust enough to prevent damage. “Expendable” rockets are disallowed from competing.

II.       Bottled Air Rules

1)   Only bottled atmospheric air is allowed. No exotic gasses, cryogenics or combustibles.

2)   Tanks must be certified. (copies of tank certifications will be provided and filling station receipt).

3)   All local laws must be complied with for handling pressurized tanks as well as any certifications that the operator may need will also be provided upon a record submission.

4)   To prevent "stomp rockets" the rocket must remain pressurized to full launch pressure for a period of no less then ten (10) minuets. (The ground view camera will show both the tank and rocket on the launcher during this 10 minute period).

5)   Bottled air pressure source must be located at the minimum safe distance of 50 Feet (15 meters) from the launcher (this allows the bottle air pressure source to be safely controlled in the event of an emergency).

III.      Safety Rules

1)   All WRA2 Water Rocket Safety Rules must be followed.

2)   All launched parts of rocket which travel over  6 meters (20 feet) in altitude must have a recovery system which limits their descent rate at time of touchdown at ground level to a maximum velocity of 10 meters/second (33 feet per second) This includes all pieces which separate or are shed off in flight. Fast falling rockets, boosters, debris, or rocket parts can be very dangerous. Recovery system malfunctions for any part will disallow any record flights.

IV.     Pressure Vessel Rules

1)   Rocket cannot exceed 1,500 grams empty (no reaction mass)..

2)   Pressure vessel must be entirely fabricated by the rocket builder.

3)   Pressure Vessel cannot be constructed using any portion of an existing high pressure enclosure. (i.e. no Paintball tanks, CO2 tanks, SCUBA tanks, Propane Tanks, etc.). The object is to engineer and build your rocket yourself.

4)   Pressure Vessel and all external parts of the rocket may not be fabricated from metal. (see the WRA2 water rocket safety rules).

5)   Pressure vessel must be entirely fabricated by the rocket builder.

V.      Reaction Mass Rules

1)   Reaction Mass must be primarily ordinary tap water.

2)   Thrust must come from expelling reaction mass, not from air discharge. That would be considered an Air Cannon projectile.

3)   Water Reaction Mass must fill a minimum of 20% of the volume of the Pressure Vessel. Token amounts of water added in an attempt to qualify an air cannon projectile as a water rocket are not allowed.