Corrected entry: When Marty goes to burn the Almanac near the end of he movie, he drops the hoverboard on the ground and it noticeably wobbles very fast when it lands. A hoverboard wouldn't do that, as it would just float normally if it was dropped.
csteel310
26th Jul 2003
Correction: We don't know how to turn the hoverboard on or off, and during the movies, it goes on and off several times, for instance when it is in the back seat of the DeLorean it is off, but when Marty pulls it out, it turns on. It may have been off in this scene.
Sol Parker