I'm trying to distinguish land from ocean in harbors in Matlab. I have tried using the highest resolution maps from gshhs, but it isn't detailed enough. Below are is an example showing that it isn't detailed to the level I want. The one to the left showing the coastline boundaries and the other one showing the geoplot with basemap = 'streets'.
Comparison of the basemap and coastlines:
Since the map is able to plot in such detail, shown below, I would imagine that it should be able to distinguish land from ocean, just based on the colors.
Zoomed in basemap:
Appreciate any help here! Thanks in advance.