I lived in Belgium in the '70's as a kid (my father was U.S. Army and we were stationed there for three years.  I started collecting militaria while over there and one day picked up this helmet at our local Sunday morning flea market.  While it seems obviously a motorcyclist's helmet, I'm not certain who would wear this.  Is it military, police or post office?

 

 

Any education appreciated.

 

 

 

It's not Belgian but Dutch, a motorcyclist's helmet indeed of the Koninklijke Marechaussee, the military police; 1950's/60's-era. The blue line indicates how deep you had to push them under water, or so the story goes.

 

 

 

 

Outstanding!  I appreciate it.  Makes sense finding it in Belgium.