Seabed logging is a direct and remote application of control source electromagnetic method to detect the hydrocarbon reservoirs. In this method, electromagnetic waves are used to detect the resistivity contrast between the various sediment layers. In this study, a semicircle antenna is used as the source of electromagnetic waves for detection of the resistive layers under the seabed. Numerical solutions of the electric field wave equations in time domain are derived. Results on the effect of seawater depth, and thickness of hydrocarbon on the electric field have shown that antenna is able to assist in hydrocarbon detection. © 2021, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.