I have very fond memories of flying water rockets when I was too young to use fly anything that involved combustion. But
existingsystems I now see are alleither simple and uncontrollable or complex and expensive; and all of them are inefficient.
This led me to design a new water rocket system, okay the "World's Best" title is subjective! But my system is simple, with only three bespoke plastic parts, therefore cheap to make and assembled by the consumer; intrinsically safe, so therefore able to employ higher air pressure for much better flights; and controllable, have a real countdown rather than cringing round a corner waiting for it to launch at some point!
In keeping with user friendliness, it will work with any standard plastic carbonated soft drinks bottle, though bespoke bottles would give better performance still. A working prototype is available for demonstration and CAD files are ready for tooling in all major 3D interchange formats.
If you are interesting in licencing the latest thing in garden rocketry do mail me at firstname.lastname@example.org