Three shiny spheres over Graham Texas

While water skiing late one fall afternoon on Lake Graham, we saw something unexplainable.  
I was driving the boat with my dad behind on skis.  Mom was a passenger.  
Dad started pointing frantically to the South.  About 20 degrees above the horizon were three shiny ball shaped objects sailing along in perfect triangular formation in an easterly direction.  They turned North as they moved across the bow and their shape never changed.  
The sky was clear blue.  
They accelerated and vanished.  
I’ll never forget it.
Witness indicates that date of incident is approximate.  PD