A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Robert VanderPol II
Date: 2017 May 21, 09:53 -0700
In the middle of the ocean it doesn't matter. Approaching the Minerva reefs, Tuamotus or Chagos Archpeligos it matters greatly. All of these are low lying or awash so a navigator on a small vessel would want to be accurate to several miles rather than 10nm.
Approaching the Tuamotus at night on would want to heave to an wait for daylight before approaching and entering. The currents in this area can be very random. You might think that stopping 20nm from the atolls would be sufficient but if you are actually 10nm or so closer, between 0000 and 0700 you could be swept 14-18nm closer whch would put you into the atolls and shallows.
There are plenty of places where you want better accuracy or at least a better idea of what the errors in your position are likely to be.
Re: Position errors for 2- and 3-body observations
From: Randall Morrow
Date: 2017 May 16, 17:46 -0700