Each tapered tunnel section extends from the propeller section to a tunnel opening through {HEAD ~ a hull} of {TAIL ~ the vessel} 
Each tapered tunnel section extends from the propeller section to a tunnel opening through { HEAD ~ a hull } of { TAIL ~ the vessel }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL