US has army, navy, air force,Marine Corps, and coast guards as five different constituents of its large military. Similarly, countries having no coastal areas need not have navy and different units are raised and maintained depending upon needs and requirements...
Figure 1. Maps of (a) Kavala, Greece, with numbered marks indicating the survey stations (N = 19) (Google Earth; Image Landsat/Copernicus, Data SIO, NOAA, U.S. Navy, NGA, GEBCO; ©2020 Google, Image©2021 TerraMetrics, Image©2021 Maxar Technologies, inset: ESRI, HERE, Garmin,...