dRlocP=rC(k)-rF(k+1)
dRlocP=halfRL*drC(k+1)
& +dRlocP*gravity*alphaRho(i,j)*recip_rhoConst
& +MIN(zeroRL,ddRloc)*rec_dRp*dRlocP
phiHydF(i,j) = phiHydC(i,j) + dRlocP*alphaRho(i,j)
_RL dRlocM,dRlocP, ddRloc