In strong oceanic turbulence, the performance of M-ary phase shift keying subcarrier intensity-modulated optical wireless communication (OWC) links is investigated in terms of the bit-error-rate (BER) by considering the effect of anisotropy of the oceanic channel. To calculate the BER of the OWC link, a gamma–gamma statistical channel model is adopted. The extended Huygens–Fresnel principle and the asymptotic Rytov theory are used to obtain the received optical power and the large-scale and small-scale log-intensity variances, respectively. Our graphical illustrations include the BER versus anisotropic factor for various system parameters such as the modulation order, filter bandwidth, link distance, peak amplitude of each subcarrier and the oceanic turbulence parameters.