Lift the bath above your heads using only wingardium leviosa with no additional charms, and proceed past the tree.
“It’s too slow to walk backwards!
“Let’s run sideways!”
“Levitate the water separately..?”
“Not sure we’ve got time to debate!”
The fourth years were cooperating as best they could between them it seemed, given the little time they had been given to consider the task. The first team crossed the line, and dropped their bath, shrieking at how wet they were. Wakahisa begged Antonopoulos to put their bath down partway there, ó Fearghail and Pepper were marching in time like soldiers and coming up quickly.
The Professor gestured to those at the tree to wait, and some of the students leaned against the baths as they caught their breath, calling encouragement (or discouragement in the case of Slytherins) to the rest of them.
“Haven’t got all day, Wakahisa, Antonopoulos,” the Professor called, trying to spur the girls back into action.
OOC: Feel free to have them all reach the tree in your next post