We consider wave propagation in a fluid containing parallel porous cylinders randomly distributed in space. The effective wavenumber of the coherent wave in the medium is derived at the Rayleigh limit for explicit formulas ISA (Independent Scattering Approximation), Waterman and Truell (WT) and Linton and Martin (LM) as well as for implicit formulas, i.e. CPA (Coherent Potential Approximation) and GSCM (General Self Consistent Method) applied to WT and to LM. When the porosity of the cylinders tends to zero the well known cases of an assortment of random elastic cylinders in fluid is found
