BLUSH>>> just a quick nav question..........When refering to position via VHF as of stating your boats position,,,what is first discribed??? Longitude???...or latitude??? thanks
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G
Gord May
T
Ted
N,S,E,W
Also the N,S,E or W as shown on Mr. Mays reply should make it clear to the listener which is which.
Also the N,S,E or W as shown on Mr. Mays reply should make it clear to the listener which is which.
An easy way to remember
Back when I was a kid, a flight instructor taught me an easy way to remember which comes first...you do them in alphabetical order. LA comes before LO...so you give your latitude first followed by your longitude. Another one is that latitude sounds a lot like altitude, which is how far up or down you are, like north and south, so you don't get them confused. Probably a bit simplistic, but for a 15 year old kid to understand, it seems to have worked. Hope this helps, Jeff
Back when I was a kid, a flight instructor taught me an easy way to remember which comes first...you do them in alphabetical order. LA comes before LO...so you give your latitude first followed by your longitude. Another one is that latitude sounds a lot like altitude, which is how far up or down you are, like north and south, so you don't get them confused. Probably a bit simplistic, but for a 15 year old kid to understand, it seems to have worked. Hope this helps, Jeff
T
Tom
T
tom
A bearing and distance might be better
In an emergency type situation a bearing and distance might be better. Obviously if you are reading off your GPS or LORAN give the lat and lon. But if you are dealing with an accident or sinking it might be easier to say "I am 2 miles north of Dauphin island"" , or, "1 mile at 180 degrees off big Beacon light"" . Because first you'd have to determine your position on a chart then translate that to lat/lon introducing another source of error. If someone hears your call and responds first they'd have to do lat/lon on their chart then determine their location. Just a thought. I've found that the brain is prone to mistakes during stressful situations so as they said in the Air Force..."Keep It Simple Stupid"
In an emergency type situation a bearing and distance might be better. Obviously if you are reading off your GPS or LORAN give the lat and lon. But if you are dealing with an accident or sinking it might be easier to say "I am 2 miles north of Dauphin island"" , or, "1 mile at 180 degrees off big Beacon light"" . Because first you'd have to determine your position on a chart then translate that to lat/lon introducing another source of error. If someone hears your call and responds first they'd have to do lat/lon on their chart then determine their location. Just a thought. I've found that the brain is prone to mistakes during stressful situations so as they said in the Air Force..."Keep It Simple Stupid"
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RonD
Comm Procedure
In coastal waters, the Coast Guard typically prefers to work from a bearing/distance relative to a fixed object, or set of bearings. It's much easier & faster to plot & can be correlated by their Radio Direction Finding (DF) equipment, if available. Transmission of bearings is generally less prone to errors compared to Lat/Long positions. Be sure to indicate whether you are reporting True or Magnetic bearings. Distance is generally in Nautical miles. Offshore (i.e., out of sight of fixed references) you should use Lat/Long, generally in degrees/minutes. Remember the latitude is given as degrees in two digits, followed by seconds in two digits, followed by North or South. One decimal place precision for "minutes" is generally OK; don't waste transmission time going to any greater precision. MY POSITION IS LATITUDE FOUR THREE DEGREES TWO SIX DECIMAL ZERO MINUTES NORTH Longitude is given as degrees in three digits, followed by seconds in two digits, followed by East or West. LONGITUDE ZERO SIX NINE DEGREES THREE ZERO DECIMAL ZERO MINUTES WEST You should then follow that by your present speed and course information. SPEED SIX DECIMAL ZERO KNOTS COURSE TWO FOUR ZERO DEGREES MAGNETIC That position, by the way, would put you near the northern edge of the inbound side of the Portland, ME Eastern approach traffic separation zone. If you could see & identify Portland Head Light from your boat (unlikely!), it would roughly correspond to a bearing of about 121 degrees magnetic from Portland Head Light on Cape Elizabeth, at a distance of about 32 nautical miles. And put you on a course toward the Cape Ann, MA area. --RonD
In coastal waters, the Coast Guard typically prefers to work from a bearing/distance relative to a fixed object, or set of bearings. It's much easier & faster to plot & can be correlated by their Radio Direction Finding (DF) equipment, if available. Transmission of bearings is generally less prone to errors compared to Lat/Long positions. Be sure to indicate whether you are reporting True or Magnetic bearings. Distance is generally in Nautical miles. Offshore (i.e., out of sight of fixed references) you should use Lat/Long, generally in degrees/minutes. Remember the latitude is given as degrees in two digits, followed by seconds in two digits, followed by North or South. One decimal place precision for "minutes" is generally OK; don't waste transmission time going to any greater precision. MY POSITION IS LATITUDE FOUR THREE DEGREES TWO SIX DECIMAL ZERO MINUTES NORTH Longitude is given as degrees in three digits, followed by seconds in two digits, followed by East or West. LONGITUDE ZERO SIX NINE DEGREES THREE ZERO DECIMAL ZERO MINUTES WEST You should then follow that by your present speed and course information. SPEED SIX DECIMAL ZERO KNOTS COURSE TWO FOUR ZERO DEGREES MAGNETIC That position, by the way, would put you near the northern edge of the inbound side of the Portland, ME Eastern approach traffic separation zone. If you could see & identify Portland Head Light from your boat (unlikely!), it would roughly correspond to a bearing of about 121 degrees magnetic from Portland Head Light on Cape Elizabeth, at a distance of about 32 nautical miles. And put you on a course toward the Cape Ann, MA area. --RonD
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CAPTAIN JOHN EDWARDS
T
Ted
Vessel Assist
In our area Vessel Assist always requests a GPS coordinate if available, I know from personal experience (someone else's boat) that they also have radio direction finding equipment. In this case (no GPS) I gave them a bearing and distance (owner didn't know where we were) and they used RDF to fine tune their course when they were in the area. Be careful who you go out with.
In our area Vessel Assist always requests a GPS coordinate if available, I know from personal experience (someone else's boat) that they also have radio direction finding equipment. In this case (no GPS) I gave them a bearing and distance (owner didn't know where we were) and they used RDF to fine tune their course when they were in the area. Be careful who you go out with.
R
Rick
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