Originally Posted by PCP
I don't understand your logic. I am talking about guys that have a blind faith on the absolute precision of the plotter, like the captain of rule 62. If I was one of those and if I was navigating at night and blindingly trusted the plotter without giving a big berth to its information and was passing 100m at starboard of that rock I would have hit it.
I am not saying that the plotter is not very useful. See my previous post. I am saying that the plotter can be very dangerous for the ones that trust blindly its information and I am quite sure the Captain of Rule 62 is not the only one.
This goes back to the well known principle of never trusting one nav device. I have noticed errors in chartplotters that would have me navigating on pavement. As noted above, this is due to many different factors. In reality, all navigation relies on a number of inputs. The plotter is a great tool and added to the other inputs, certainly makes life easier but I would not blindly trust it, especially at night when even more attention needs to be paid to light patterns, atmosphere, depth, and even sound.