listing depth values
Following Paul's suggestion I have found this little script easily produces coastline files
/opt/gmt/bin/gmt pscoast -R-121/-119/33.5/35.1 -M -W -Df > SantaBarbaraChannel.txt
Being greedy, I now want to also have available depth values within the area enclosed by the coastline
output is any convenient way (.txt, .rtb, .nc or even binary)
RE: listing depth values - Added by Federico 17 days ago
You could create a mask (a grid) from the closed polygon (see grdmask), and then multiplied it with your bathymetric grid (grdmath). Both grid must have the same region and resolution.