Thanks for the reply.  Not getting much response to topography issues but it is planting season.  I do have RTK but have never post processed a field.  I don't have to walk into the water but thought it would be a reasonable cost alternative for the WAAS or BEACON gps guy as a place to start.  Then if he noticed something with those points on a yield map he could then use someone to do GIS work on his data sets with good accurate elevation data and work up some correlations etc.

Thanks for the post back.

Arnie