{TAIL ~ A compressed boat} may be assembled from {HEAD ~ two substrate boats}, one of which moves away from the other during loading and unloading 
{ TAIL ~ A compressed boat } may be assembled from { HEAD ~ two substrate boats } , one of which moves away from the other during loading and unloading
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH