Sky high at sea level
You can bump into anything on Crissy Field next to San Francisco Bay. I thought they might have flow in in from somewhere, but their instructor told me they were just practicing -- maximum altitude while I watched was one foot (the guy in yellow). I asked them if they planned to go off of Mount Tamalpais-- but they said no, next stop was a low dune and besides they needed to check out relations between the parasailors and the hang gliders on Mount Tam. I recropped the photo to take out some grass at the bottom of the photograph.