If we approximate water as incompressible then cp=cv=c and cp/cv = 1. but if we consider water as compressible and use Tait EOS (in which density is only function of pressure) then how to find cp/cv for water? I have already tried cp/cv = beta_t/beta_s (where beta_t is isothermal compressibility=-(1/V)(dv/dp) and beta_s is isentropic compressibility =   -(1/V)(dv/dp),  usign Tait EOS and ans is 1). Therefore I need another solution. Please suggest. Thanks in advance.