We've just returned from a week's sailing in Mexico on a boat with a chartplotter, latest available "charts" and radar. The official charts of the Mexican coast are appallingly bad.... every where we anchored the plotter showed us to be up to a 1/2 nm "inland".
Making a landfall (or simply negotiating a group of islets or a headland) in the dark in this region without radar would be scary as hell. Radar is so much more than a tool for collision avoidance with another vessel.
".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)
1984 Fast/Nicholson 345 "FastForward"