contour map generation

[31CHALLAS at wmich.edu]

I am having x,y,z co-ordinate survey  data obtained from boat survey.
How can I generate contour map from this data. How to incorporate the
ground reference points. One more thing is if we want to lay pipelines
8meters below the ground surface along a fixed route, is there any 
procedure to findout at which points the pipeline will be exposed.
I am not a subscriber. so pl give reply to my email address.
Thanks for any help.
challa
31challas at wmich.edu