Cub Scouts' annual water rocket launch. the 161 scouts took soda bottles (2 liter variety and smaller), and built them into the shape of rockets using duct tape and cardboard (for the fins). They then filled them with a little water and a lot of compressed air and launched them hundreds of feet into the sky.
The videos were courtesy of former Cubmaster Chandler Dickinson who brought a small keychain-sized video camera and mounted it onto the rockets. So we all got a rocket's eye view of the flights.
The actual launch took place adjacent to the Pavilion at Austin Park and that is Sims Field (the baseball field) that you can see in the videos.