The effect of sediment shear wave propagation on bottom reflection loss (RL) from a typical deep sea sediment layer is analyzed by means of a ray path decomposition of the acoustic field. The amplitude of each shear (S) and the compressional (P) ray is obtained from the interface reflection and transmission coefficients. These coefficients are analyzed by means of an expansion in the parameter ε which is proportional to the relatively smallS‐wave velocity of marine sediments. Ray paths with amplitudes up to order ε2are identified and used to develop a qualitative ray path model of RL.P‐wave conversion at the sediment–substrate interface is the dominant mechanism for sedimentS‐wave excitation. To order ε2, RL is the result of the interference of three waves in the water whose amplitudes are proportional to ε0, ε1, and ε2. Comparison with RL obtained from a computational model shows that the ray path model correctly predicts the dependence of RL on frequency,S‐wave speed,S‐wave attenuation, andP‐wave attenuation.