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Chuck,
I think you misunderstood the thrust of my remarks; maybe I didn't make them as clearly as I could have.
First, I totally agree on the use of ALL AVAILABLE MEANS to find and fix your position at sea. GPS is a wonderful tool. That's why I carry two identical Furuno units (with two other handheld backups). But I also carry a host of other navigational tools, both electronic and other.
I also agree on the use of routes. Normally, when under power or sail I have a preplanned route with waypoints displayed on the PC chartplotter. At a glance, I can then see where the good water is and where the GPS has positioned my vessel on the chart (not the same as where my vessel actually is, though close). I can then sail or power "off track" anywhere I like, but have a quick visual reference to the preplanned route.
My point is this: many sailors these days rely exclusively on their GPS-derived position as plotted on an electronic chart. This may or may not be an accurate representation of where they actually are, given the many sources for error including, inter alia, differing chart datums, charting errors, electronic glitches, etc. To my mind, this is dangerous.
Furthermore, to go that extra step and hook up your GPS to your autopilot so that the GPS is actually steering the vessel is, potentially, dangerous as well. Not because it isn't very accurate most of the time, but because to do so may psychologically relieve the user from the chore of steering and paying very close attention to navigating the vessel.
There are numerous documented instances of "GPS-assisted groundings" of small and large vessels, not usually because the GPS was wrong but because of misconceptions about its use and limitations. As good navigation practice and expertise is being seriously eroded in new generations of sailors, I think we're going to continue to see these increase.
Navigation is both art and science. The new electronic tools make it all too tempting to just forget about the art in favor of the science. This makes for dumbed-down navigators who are eventually going to come to grief, if they sail long enough and far enough.
Bill
S/V Born Free
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