As Clipper pushes the lever forward, the crab moves in that direction, although slowly. (It felt like some gears caught when the lever moved forward, and that it isn't the position of the lever that controls the speed. You figure this is controlled most likely by twisting the shovel-handled control.)
You all can feel the many legs of the contraption scuttling around, but the ride itself is quite smooth, considering. The crab slowly glides into the dark water, and the surface of the underground lake is soon above your heads. Despite the transparent roof, you can't see a whole lot down here, as it is rapidly getting very dark the deeper you go.