A shipboard communications system for providing RF communications between a ship and a communications satellite includes a modem, an antenna selector switch coupled to the modem and to a pair of directional antennas, a programmable controller for each antenna, and an antenna selector logic (ASL) circuit coupled to each antenna's programmable controller responsive to the programmable controller whereby an antenna handoff occurs when an on-service antenna is moving into a blockage zone and does not occur only when an off-service antenna is coming out of blockage.