This "Ground Effect" is Water

  Watching the pelicans skim just mere inches above the water, I pondered why and how they managed to do it.  While any pilot can probably explain the technique and the reason, I was at a loss.  Those big birds that are a mite clumsy on foot seem to be the most graceful as they fly.  Turns out, skimming is a tried and true technique.  The skill involved is great, in itself, but the bird understanding things like airflow, drag and lift is truly amazing.  With their wingtips literally touching the water's surface at times, the birds are flying most efficiently.  

  When flying low to the surface, the pelican's wings compress the airflow and increase lift while decreasing drag.  This is called "ground effect" in some aerodynamic terms. Well, duh!  I should have known that!  Not really.  Stuff like that just flies by my brain as fast as the winds of a hurricane.  But...now I know.  The pelicans are actually aware of what they are doing.  They glide effortlessly over the surface using ground effect.  It tickles me that the ground effect in this case involves water.  Smart birds. Wonders never cease.