"which leads me to ask, are they somehow CW-literate, too...?" They are probably as CW literate as most pilots that rely on NDB's (do they any more?) Their charts literally have dots and dashes listed for the various beacons. I'm guessing the fishermen have a similar, albeit less organized, methodology.
73, John KB5NJD/WG2XIQ _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK