https://www.myroms.org/wiki/easygrid The rho-grid represents the grid centers (red dots) The u-grid represents the grid East-West sides (blue triangles) The v-grid represents the grid North-South sides (green triangles) The psi-grid represents the grid corners (purple crosses) A useable Thredds example is here https://ecowatch.ncddc.noaa.gov/thredds/dodsC/northwest_fisheries/roms/nep_c.nc

plot_cgrid(
  x,
  ex = extent(0, 15, 0, 20),
  include = c("u", "v", "rho", "psi"),
  cell = TRUE,
  ...
)

Arguments

x	ROMS file
ex	extent in index space
include	grid elements to plot (all by default, uv, rho, psi)
cell	draw the cells (defaults to TRUE)
...	arguments passed to plot