New formulas for the components of the electromagnetic surface wave propagating along the boundary between sea water (Region 1) and a one‐dimensionally anisotropic rock (Region 2) have been obtained. The conductivity of the rock is taken to be &sgr;x=&sgr;y=&sgr;T, &sgr;z=&sgr;L, wherezis perpendicular to the boundary. Both &sgr;Land &sgr;Tare constant. When &sgr;L=&sgr;T, the new formulas coincide with those of Wu and King [Radio Sci.17, 521, 532 (1982); J. Appl. Phys.54, 507 (1983)] for an isotropic medium. When &sgr;L≠&sgr;T, the lateral‐wave part of the field is separated into two terms of which the first is of electric type with the wave numberk2=kL, and the second is of magnetic type withk2=kT. The new formulas can be used to interpret recent measurements of the oceanic crust.