An exact analytic solution for the propagation in seawater of low frequency electromagnetic pulse generated by an electric dipole is investigated. The dipole is excited by a rectangular current pulse with a finite, nonzero rise and decay time. The frequency-domain formulas for the downward-travelling field of horizontal electric dipole excited by pulse is Fourier transformed to obtain an explicit expression for the field that is uniformly valid in distance and time. is noted that the present analysis may be used for studying pulse propagation in any highly conductiong medium besides seawater.