A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Steve Dunlop
Date: 2018 Sep 25, 08:51 -0700
<<It all depends on how much you want to spend on your chart plotter. ECDIS grade chart plotters will maintain a DR plot based on heading input (compass) and log (typically sonar) if GNSS inputs are lost (the alarm alerting you of this makes an racket). >>
Right now I'm using my phone, but I'm looking at OpenCPN and standard products from B&G and Raymarine. I don't know what they are actually capable of.