Inaccurate?

Floating Disk, Greater

(Spell Compendium, p. 96)

Evocation [Force]
Level: Sorcerer 4, Wizard 4,
Components: V, S, M,
Casting Time: 1 standard action
Range: Close (25 ft. + 5 ft./2 levels)
Effect: 3-ft.-diameter disk of force
Duration: 1 hour/level
Saving Throw: None
Spell Resistance: No

Letting the mercury drip to the ground you create a slightly concave disk of energy. It hovers several feet above the ground.

This spell functions like _Tenser's Floating disk (PH 294), except that the created disk does not need to stay within 3 feet of the surface beneath it. However, the disk must remain within 15 feet of you at all times. You can concentrate (as a standard action) on the disk to make it move with a fly speed of 20 feet (perfect). This allows you to sit on the disk and command it to carry you about.

Material Component: A drop of mercury.