The principle of operation of spherical antennas, which were used in experiments on the transmission of a short-wave radio signal in the marine environment, is theoretically described. A solution of a spherically symmetric electrodynamic problem based on the experimentally found potential component of the magnetic field is proposed. The characteristics of a potential wave process in an electrically conductive medium are determined. The law of transformation of an electromagnetic wave at the "conductor-dielectric" interface has been established.