My wife would like a chart plotter!!
I have been coastal and offshore
cruising for 40 years with traditional navigation
methods - hand bearing compass
and chronometer etc and am more that content with this but.... my wife wants a chart plotter.
My knowledge of these things is limited to what can be gleaned in 5 minutes from a salesman and I can see that they may have some value but I have a couple of questions please.
(1) I don't see any means of inputting offsets into the plotter. All my paper charts
are WGS84, and some have a GPS
derived position plotted directly on them, and some require a GPS
derived position to be plotted with a correctional offset. Since I presume that electronic charts
are derived from paper charts, what happens here in chart plotter world, and in fact how do you know where if offsets are even required? The reason for my concern is that a short time ago, one of my company's ships, a 22,000DWT multi-purpose cargo vessel had a GPS assisted grounding off the Japan
coast due to offset error.
(2) How convenient is to work with a small portion of the chart on a small screen
? I am imagining the scenario of working on a large scale paper chart, bringing your vessel to anchor
in a small bay for example. Although you are concentrating on the small bay, you are still aware of the rest of the chart and any rocks, reefs
etc in your immediate area. In chart plotter world you only have displayed the small bay - the rest of the chart is off in electronic never-land. Is this problematic?
(3) If you install the thing in the cockpit
, on the steering pedestal
for example, can you really see the screen
in bright sunlight?
(4) Are they worth the money
Any assistance greatly appreciated.
Joke & Chris