Is there a difference between a Chartplotter and a Mapping GPS? Is there a difference in the information that they provide?
I've experienced what others have noted: It's the maps/charts that are loaded into the GPS that lack accuracy and not the Lat/Long the GPS is providing. Someone once told me many charts outside of US waters were originally made just after WWII... and have never been updated!
However, I did use a Mapping GPS for primary navigation (no boat instrument at the time) sailing from San Diego into San Francisco. We made port late each evening, stayed within 5 miles of shore, and did NOT have any navigational problems... Until, in the Suisun Slough, the GPS had us crossing land
Like anything else, navigation by GPS requires some common sense. Oh, and actually believing what your eyes are telling you when you're NOT fixated on the tiny screen
J/36 "Zero Tolerance"