How is the far-field elevation pattern of a vertically polarized antenna affected by being mounted over seawater versus soil?

The ground beneath an antenna acts as a crucial reflector that heavily influences the antenna's far-field radiation pattern, especially for vertically polarized signals. Ground conductivity and dielectric constant dictate how efficiently this reflection occurs. Seawater is an outstanding electrical conductor, vastly superior to typical dirt, soil, or rock. When a vertical antenna is mounted over seawater, the highly conductive surface reflects the radio waves with very little loss. This efficient reflection greatly reinforces the signal at very low elevation angles, which is ideal for long-distance (DX) skip propagation. Therefore, mounting over seawater increases low-angle radiation compared to mounting over soil.