As an action, a creature that you can see within 5 meters is not hindered by difficult terrain made of sand.

Augment

• You can target one additional creature for each additional mana expended. The creatures must be within 5 meters of each other when you target them.

• You can expend 1 additional mana so the creature can move across any sandy surface—such as loose sand or quicksand—as if it were harmless solid ground.

  If you target a creature submerged in sand, the spell carries the target to the surface of the sand at a rate of 10 meters per turn.