There's no WAAS or DGPS in the South Pacific
... and you should also know that nearly all of the charts
in plotters, and on paper, for the South Pacific
are out in longitude and some in latitude
I was amazed last season at the number of boats that hit reefs
, islands even, cos they weren't where the skippers plotter said they were.
The plotter charts
are based on the paper charts and some of those, notably Tonga
, go back to 1867 !