That means that when traveling by ship, one does not notice the undulations of the geoid; the local vertical (plumb line) is always perpendicular to the geoid and the local horizon tangential to it.
Punika maarti wantah dugas mamargi antuk kapal, jadma nenten nguratiang undulasi geoid; vertikal lokal (garis tegak lurus) satata tegak lurus saking geoid miwah cakrawala lokal masinggungan tekennya.