For long-range surface-wave communications over seawater, what polarization is most effective?

The most effective polarization for long-range surface-wave communications over seawater is vertical polarization. This is largely due to how electromagnetic waves interact with the conductive surface of the seawater. When radio waves are transmitted with vertical polarization, they can couple more effectively with the surface of the sea and are less likely to be absorbed.

In this scenario, the vertical electric field aligns better with the prevailing propagation characteristics over a conductive medium like seawater, which helps maintain the signal's strength over greater distances. Additionally, vertical polarization tends to be less affected by ground reflections and offers better diffraction, contributing to more reliable communication in long-range maritime applications.

Horizontal polarization, while useful in other contexts, does not exhibit the same level of efficiency in this particular environment, as it can experience more significant attenuation when interacting with the seawater’s surface. Other polarizations like diagonal and circular are also less optimal compared to vertical in this context, as they do not align as effectively with the natural conditions of the surface wave environment.