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