I think this thread is conflating 2 issues that are related but separate:
1) the use of a chart plotter vs paper charts
to represent the area around you while underway.
2) determining where you are relative to all the hard and pointy things around you.
In 1) the use of a chart plotter strongly implies but does not require the use of a GPS
to determine your position. Assuming a GPS
is the source navigation
functions procede very rapidly and with minimal effort required on the part of the user. Paper charts
are not subject to power failures. Both are susceptible to salt water
In 2) Significant portions of the world are well mapped with respect to one of the datums most GPS units carry loaded and GPS positions on a map will corrospond very closely to the real world. On the other hand many areas are not. Somebody (gosailingnow?) mentioned maps being in error by up to 5nm). In error compared to what, WGS84 datum? If the map was drawn to a sextant/astronomical datum which assumes a spherical earth the GPS is going to be in error to the map because it does not pick the correct datum to referrence. Almost all maps are very good at showing the correct relative positions of visible objects and so confer the utmost trust when positions are established by site and to a certain extent by radar
. Maps vary in how good they represent the position of things relative to the world at large, ie lat/long.
issues aside, the chart plotters will have the advantage in areas that are well mapped to a GPS datum.
Paper charts have the advantage when datums are not so good.