Gravity-boarding
From Tardis Wiki, the free Doctor Who reference
Gravity-boarding, sometimes shortened to Grav-boarding, was an extreme sport in the 26th century. Gravity-boarders would ride on a levitating gravity-board, a device similar a snowboard that flew just above the ground.
Drew and Hayd went Grav-boarding at the Martian Lunar Park on Phobos. (AUDIO: Phobos)
