SHIPFL

     SHIPFL is a logical variable which indicates whether the surface 
     file contains stations which are not at a fixed location, such as 
     moving ships, aircraft, or floating buoys.

     A ship file will store and write data differently from a standard 
     GEMPAK surface file.  However, these files can be read using the 
     surface library and all programs which access data in surface files 
     can be used unchanged.

     Note that station information cannot be added to these files, since 
     the station information must be stored with the data.