I am stage managing for a fairly large amateur play, and one of the requirements from the director is that we have a large river that the cast can interact with. the river will have to be on the floor in front of the stage, with all the seats pulled back. The best idea that i've come up with is to hire a nitrogen low flying fog machine (courtesy of a large budget) and enclose about 4 or 5 metres of the floor with raised river banks, which would be able to support the weight of the actors. Then we could simply fill that enclosed area with smoke, and the air conditioner vents which are underneath the front of the stage would keep the smoke slowly moving. To top off the effect we would have MAC 250 entours running a gobo over the river. so would that work, or is there another way that would work better, and for less cost?