The above image is based on a photo by Bettina Gray printed in black-and-white in the April 1979 edition of Hang Gliding magazine.

The Debauche Raven (not to be confused with the Wills Wing Raven) flown by Eileen Debauche performed well at the annual glide ratio contest held in February 1979 at a low hill in San Diego.

The glide ratio contest tests the flatness of hang gliders' flight paths. All gliders lose height while airborne, which is why you need to find rising air -- normally either ridge lift or a thermal -- in order to gain height. Glide ratio is not, however, the only test of a glider's performance.

Nowadays the annual glide ratio contest is held in early morning still air at the appropriately named Morningside Recreation Area flight park in New Hampshire.