encoding  utf-8
  centreline 
    #This centreline data block enables team names and dates 
    #to be incorporated into the map headers, and allows the
    #elevation range used to colour the maps by altitude to be
    #pinned to specific ranges
    
    cs EPSG:25830
      	  
    #Highest points for system (elevations):
    # 250m = Top of Gour Inlet Aven
    # 260m = Range of passages over Entrance area including Tres Ninos
    
    #Lowest elevation points for system:
    # 40m = elevation of Boyones Resurgence
    # 80m = elevation of Downstream sump in Llueva
    
    fix top 453500 4798000 160 
    fix bottom 453500 4797900 100 
     
    top    elev1  0.01  90  0  
    elev2  bottom  0.01  270  0  
  endcentreline