Reversed axes and connect the dots?

Q1:In oceanography it's customary to have a "reversed" axis for depth. 
For example, a 2D plot of some measured value (like salinity) ert to 
depth, the origin of the Y axis is at the top of the axis and 
represents the surface of the ocean. Depth increases down the axis 
rather than up from the cartesian origin. Is there any way to tell 
VisAD to draw a reversed axis?

Q2: I have succeeded in producing 3D scatter plots where the plot 
symbol is colored by another measured variable. Is there a way in VisAD 
to connect the plotted points with a line segment? If so, can the line 
segment also be colored by the color variable? 

Thanks

oz
NOAA/PMEL