The rigid balloon has a chamber to hold lighter-than-air gas portions to retain a structural member or members and a separate light gas is filled into the chamber through a valve in the balloon. Structural members are inserted into the portion to help retain the desired shape of the balloon. The structural members also provide a counterbalancing weight which prevents the balloon from floating upward. Thus, the balloon, once released into the air, will retain its shape and remain floating at the height from which it was released unless repositioned.