{HEAD ~ The foremost edge} of {TAIL ~ the hydrofoil} comprises a slot covered by a continuously adjustable gate for controlling the overall drag imposed by the turbine 
{ HEAD ~ The foremost edge } of { TAIL ~ the hydrofoil } comprises a slot covered by a continuously adjustable gate for controlling the overall drag imposed by the turbine
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH