Analytical methods are used to express the dependence of low‐frequency bistatic reverberation on the power and direction spectra of the time‐dependent sea surface. The 3‐D cross‐spectral density (CSD) of the reverberation is obtained, to second order in the small‐waveheight approximation, as a sum of dc and sideband terms. For numerical simulations, this theoretical formulation is applied to a model ocean consisting of a homogeneous half‐space. The sensitivity of the CSD to the power spectrum of the source, the power and direction spectra of the surface, and bistatic source/receiver geometry are assessed for both the zero‐Doppler components and the Bragg–Doppler sidebands. [Work supported by ONR.]