{HEAD ~ The side edges} 2 slope inward from {TAIL ~ the top} of the body board T to the bottom surface B 
{ HEAD ~ The side edges } 2 slope inward from { TAIL ~ the top } of the body board T to the bottom surface B
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH