This allows a gas pressurizing blower to either maintain {HEAD ~ cushion gas pressure} for {TAIL ~ minimum draft} or evacuate the gas cushion from minimum above water profile 
for
This allows a gas pressurizing blower to either maintain { HEAD ~ cushion gas pressure } for { TAIL ~ minimum draft } or evacuate the gas cushion from minimum above water profile
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH