I'm going to replace the stock tray turf on our 08 SJ. We ride on flat water, but do jump large cruiser waves.  I don't know much about under-mat foam padding, but sounds like it would be way more comfortable.   
Do you just glue it down first and then glue the turf to it? What thickness, I see several types?
			
			Do you just glue it down first and then glue the turf to it? What thickness, I see several types?
 
				 
 
		 
 
		 
 
		
 
 
		