Gmax flat surface upgrade for 2k4

I have recently (hah!) noticed that the new SDK's contain a Gmax [thingy] that flattens aboveground surfaces and allows you to land on them. I assume this was created for making aircraft carrier decks, but I am interested in creating and offshore rig with runways, raised some 50 or 60 meters off the water. Is this possible with these new Gmax improvements?