Chris Garrett from Pratt Whitney Rocketdyne is a water rocketeer. I've just found the website of another: George Kurtz. Check out the evolution of his efforts with what the Air Command Water Rockets. He has great construction tips for the next step.
His blog covers the day to day progress of water rocket development by the Air Command Water Rockets team (for example, launch reports). It is also a facility for people to provide feedback and ask questions.
George lead me to Dean's Benchtop. Dean Wheeler is another water rocketeer. His website has online simulators specific for water bottle rockets to allow SECME students the ability to predict before they produce.
