You're right. AIM 1-1-20(a)(8) tells us that we should not use GPS altitude.
When WAAS is in common use this will probably change.

Bob Gardner

"EDR" wrote in message
...
In article , Hankal
wrote:

I comply.Look at my GPS which is at 7060.
I go down 50 feet the gps stays at 7060. I go up 100 feet the gps stays
at
7060.

GPS altitude is only accurate to +/-150 feet.
It is a "rough" reference, not to be considered "precise".