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#1
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Boat vs Auto GPS
I keep reading about GPS for boats and how innacurate it can be.
Why is the same not innacurate in cars? My car GPS is so accurate it tells me I am on the white line at a traffic signal stop light or in my driveway. Why not the same for boats? |
#2
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Try this for an experiment:
Cover up your windshield and drive entirely by trying to follow the line on you car's GPS system. That's what you doing on a boat in the fog. Also, consider that the streets have been well mapped in the last few years by survey companies that drive around in cars and mark each intersection. Many nautical charts are based on century old data. Much of the issue is the map/chart quality, not the accuracy of the GPS itself. Actually, the boat gps is just as accurate, perhaps even better since there is no shielding from high buildings. Its just that on a boat you may be relying 100% on the GPS as the primary, and perhaps only, source of position. In a car, you glance occasionally at the map plotter and would never notice if the GPS sometimes said you were on someone's front lawn. One can easily imagine a situation on a boat where failure of the GPS would cause you to drop anchor and wait until the weather clears; I doubt you would do the same in a car! BTW, my wife got a new car with a nav system just last night. It currently in the driveway reporting two different street addresses (depending on how you ask), both wrong. Both are actually nonexistent addresses - one of them would be a hundred yards past the other end of a dead end street. The actually position on the map is well reported, however. anchorlt wrote: I keep reading about GPS for boats and how innacurate it can be. Why is the same not innacurate in cars? My car GPS is so accurate it tells me I am on the white line at a traffic signal stop light or in my driveway. Why not the same for boats? |
#3
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Try this for an experiment:
Cover up your windshield and drive entirely by trying to follow the line on you car's GPS system. That's what you doing on a boat in the fog. This thread is interesting! alot of things I never thought about. Tim |
#4
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We tried a WAAS enabled Garmin and were able to successfully navigate to
each of the Taps at our Sailing Clubs bar. We entered waypoints and were successful in navigating back to each tap. Unfortunately after several demonstrations, our ability to navigate back to the appropriate tap started to diminish...However, I'm reasonable sure it had nothing to do with the position displayed on the GPS. :-) -- Cheers, Jeffrey Nelson Muir Caileag C&C 30 "Jeff Morris" wrote in message ... Try this for an experiment: Cover up your windshield and drive entirely by trying to follow the line on you car's GPS system. That's what you doing on a boat in the fog. Also, consider that the streets have been well mapped in the last few years by survey companies that drive around in cars and mark each intersection. Many nautical charts are based on century old data. Much of the issue is the map/chart quality, not the accuracy of the GPS itself. Actually, the boat gps is just as accurate, perhaps even better since there is no shielding from high buildings. Its just that on a boat you may be relying 100% on the GPS as the primary, and perhaps only, source of position. In a car, you glance occasionally at the map plotter and would never notice if the GPS sometimes said you were on someone's front lawn. One can easily imagine a situation on a boat where failure of the GPS would cause you to drop anchor and wait until the weather clears; I doubt you would do the same in a car! BTW, my wife got a new car with a nav system just last night. It currently in the driveway reporting two different street addresses (depending on how you ask), both wrong. Both are actually nonexistent addresses - one of them would be a hundred yards past the other end of a dead end street. The actually position on the map is well reported, however. anchorlt wrote: I keep reading about GPS for boats and how innacurate it can be. Why is the same not innacurate in cars? My car GPS is so accurate it tells me I am on the white line at a traffic signal stop light or in my driveway. Why not the same for boats? |
#5
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Hilarious!
But as we know (and has been mentioned at length in another thread), one should not rely on a single method of navigation. I presume the GPS in this case was supplemented by celestial (if an outdoor bar), or dead reckoning??? --Alan G. "DARat" wrote in message ... We tried a WAAS enabled Garmin and were able to successfully navigate to each of the Taps at our Sailing Clubs bar. We entered waypoints and were successful in navigating back to each tap. Unfortunately after several demonstrations, our ability to navigate back to the appropriate tap started to diminish...However, I'm reasonable sure it had nothing to do with the position displayed on the GPS. :-) -- Cheers, Jeffrey Nelson Muir Caileag C&C 30 "Jeff Morris" wrote in message ... Try this for an experiment: Cover up your windshield and drive entirely by trying to follow the line on you car's GPS system. That's what you doing on a boat in the fog. Also, consider that the streets have been well mapped in the last few years by survey companies that drive around in cars and mark each intersection. Many nautical charts are based on century old data. Much of the issue is the map/chart quality, not the accuracy of the GPS itself. Actually, the boat gps is just as accurate, perhaps even better since there is no shielding from high buildings. Its just that on a boat you may be relying 100% on the GPS as the primary, and perhaps only, source of position. In a car, you glance occasionally at the map plotter and would never notice if the GPS sometimes said you were on someone's front lawn. One can easily imagine a situation on a boat where failure of the GPS would cause you to drop anchor and wait until the weather clears; I doubt you would do the same in a car! BTW, my wife got a new car with a nav system just last night. It currently in the driveway reporting two different street addresses (depending on how you ask), both wrong. Both are actually nonexistent addresses - one of them would be a hundred yards past the other end of a dead end street. The actually position on the map is well reported, however. anchorlt wrote: I keep reading about GPS for boats and how innacurate it can be. Why is the same not innacurate in cars? My car GPS is so accurate it tells me I am on the white line at a traffic signal stop light or in my driveway. Why not the same for boats? |
#6
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Yeah, definitely dead reckoning. :-)
-- Cheers, Jeffrey Nelson Muir Caileag C&C 30 "Alan Gomes" wrote in message news:C4apd.80995$V41.318@attbi_s52... Hilarious! But as we know (and has been mentioned at length in another thread), one should not rely on a single method of navigation. I presume the GPS in this case was supplemented by celestial (if an outdoor bar), or dead reckoning??? --Alan G. "DARat" wrote in message ... We tried a WAAS enabled Garmin and were able to successfully navigate to each of the Taps at our Sailing Clubs bar. We entered waypoints and were successful in navigating back to each tap. Unfortunately after several demonstrations, our ability to navigate back to the appropriate tap started to diminish...However, I'm reasonable sure it had nothing to do with the position displayed on the GPS. :-) -- Cheers, Jeffrey Nelson Muir Caileag C&C 30 "Jeff Morris" wrote in message ... Try this for an experiment: Cover up your windshield and drive entirely by trying to follow the line on you car's GPS system. That's what you doing on a boat in the fog. Also, consider that the streets have been well mapped in the last few years by survey companies that drive around in cars and mark each intersection. Many nautical charts are based on century old data. Much of the issue is the map/chart quality, not the accuracy of the GPS itself. Actually, the boat gps is just as accurate, perhaps even better since there is no shielding from high buildings. Its just that on a boat you may be relying 100% on the GPS as the primary, and perhaps only, source of position. In a car, you glance occasionally at the map plotter and would never notice if the GPS sometimes said you were on someone's front lawn. One can easily imagine a situation on a boat where failure of the GPS would cause you to drop anchor and wait until the weather clears; I doubt you would do the same in a car! BTW, my wife got a new car with a nav system just last night. It currently in the driveway reporting two different street addresses (depending on how you ask), both wrong. Both are actually nonexistent addresses - one of them would be a hundred yards past the other end of a dead end street. The actually position on the map is well reported, however. anchorlt wrote: I keep reading about GPS for boats and how innacurate it can be. Why is the same not innacurate in cars? My car GPS is so accurate it tells me I am on the white line at a traffic signal stop light or in my driveway. Why not the same for boats? |
#7
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anchorlt,
I have a hand held Garmin. When I first got it, and had tracking enabled, I piloted a course that took me under a draw bridge. The tracking showed that I was about a 1/4 mile inland, most disconcerting. I called Boat U.S. where I had bought it and was advised to "reset" the unit by depressing a button with a paper clip. After this it reported my track to be exactly right. My experience has been very positive to accuracy. Paul "anchorlt" wrote in message om... I keep reading about GPS for boats and how innacurate it can be. Why is the same not innacurate in cars? My car GPS is so accurate it tells me I am on the white line at a traffic signal stop light or in my driveway. Why not the same for boats? |
#8
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