- "A flock of a dozen or so large radials, transparent as wineglasses and fully a foot across, came floating like a flight of lost balloons above the river. A few of them drifted over to the hexapeds and settled gently on their backs, flattening over their withers like weird berets."
- ―Cordelia sees balloons in action[src]
Their ability to float came as a result of hydrolyzing water and keeping the resulting hydrogen gas. The explosive properties of that gas proved useful to Aral and Cordelia Naismith during their trek across the planet.
This activity later proved a popular recreation on Sergyar, featuring bored teens as well as Aral and Cordelia using laser pointers.