Best way to express location?

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williamabernathy

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Hi, All,
In an emergency, what's the best way to express location on the water: the traditional Degrees-Minutes-Seconds [or] Degrees-Minutes-Decimal Minutes [or] Degrees-Decimal Degrees? Or does it matter as long as the method is clearly stated?

BoatUS magazine's April article about getting towed included a sidebar about location. The point was that a boater needs to plainly state which location method is being used, instead of just rattling off a series of numbers.

Of course linking GPS to a DSC-enabled VHF radio helps, but I'm curious what's the consensus of the best way by voice over VHF.

Maybe this is in November Charlie's lane?

Thanks.

V/R
 
I'll defer to NC on the official communications but think its a good idea to include references to landmarks or navaids like 12miles SE of lost point so nearby boaters that don't thing in terms of lat/long can relate to your position.
 
I agree with mike. Lat Lon alone is good if you don't want anyone to know where you are
 
quote:
Originally posted by mdoherty

I'll defer to NC on the official communications but think its a good idea to include references to landmarks or navaids like 12miles SE of lost point so nearby boaters that don't thing in terms of lat/long can relate to your position.

Click to expand...


This.

As far as tenths or seconds, think about what format the person on the other end of the radio is going to plot that in, and what anyone responding is going to enter it in.

(It's degrees, minutes, tenths.)

EDIT: To clarify, I would broadcast a geographical reference IN ADDITION to the lat/long, not in place of.
 
The Department of Defense has standardized on Deg Min and Decimal Min as the format for coordinates. Not sure if the Coast Guard complies with this.

Using proper verbiage can eliminate confusion. The radio transmission should make it obvious what method is being used. For example:

"North 39 degrees, 45 minutes, 16 seconds"

or

"North 39 degrees, 45 Point 423 minutes"

Simply saying a string of numbers is ambiguous and should be avoided.

Mike
 
I have 2 methods push the emergency VHF DSC button then dial 505# on my Inmarsat if I'm offshore.
Either will give the correct position to the correct authorities.
Using voice would be my last choice and it depends on the emergency if the boats going under every EPIRB and PLB I have will be enabled.
If it's a serious problem I would use voice but the USCG will ask you at least 10 times to repeat your emergency and data position.
So if it's a real emergency who's got time for that?
Bill
 
If you want help soonest that probably will come from another boater not the CG or ships with staff to plot lat lon positions. Boaters know about where they are in reference to landmarks but not often the lat lon.

If they did know their lat lon they don't know without some work how far it is, and what bearing, from their lat lon position to yours. That calculation is not something they often do easily in their heads.

Every boater in the area, however, will immediately know where you are if you say you are ten miles west of Block island. Few will know where you are if you give the lat lon regardless of decimal or minutes and seconds. Northing wrong with giving lat lon after you give a landmark referenced position.

My pet peeve with the CG is asking folks to be on the look out for a vessel at a particular lat lon without any reference to land marks. I will quickly know that I should look for a vessel in distress if they say 5 miles SE of Boca grand pass but not if they give the lat lon.
 
quote:
Originally posted by meide

The Department of Defense has standardized on Deg Min and Decimal Min as the format for coordinates. Not sure if the Coast Guard complies with this.

Using proper verbiage can eliminate confusion. The radio transmission should make it obvious what method is being used. For example:

"North 39 degrees, 45 minutes, 16 seconds"

or

"North 39 degrees, 45 Point 423 minutes"

Simply saying a string of numbers is ambiguous and should be avoided.

Mike

Click to expand...


A little more accurately, I believe "North 39 degrees, 45 decimal 423 minutes" is the generally preferred verbiage for radio comms. But I absolutely agree while the L/L coordinates are by far the more accurate means of position reporting, the USCG and all others would do well to include a geographical bearing and range reference for immediate comprehension of the general area of concern . But not instead of L/L which is critical for WP input.
 
Any boat that pushes the emergency DSC automatically shows the boat in distress on my plotter.
From there it's easy for me to see if I can render assistance.
This assumes they have the DSC GPS data properly talking to their VHF radio.
Bill
 
quote:
Originally posted by pdecat

Boaters know about where they are in reference to landmarks but not often the lat lon...

Click to expand...


Less often than not.

If, hypothetically, I happened to be on the other end of the radio when someone was calling for help, and they gave me a lat and long that didn't make sense, that didn't quite jive with their geographic reference, or I just plain didn't believe them because they were giving me the impression they didn't have any idea what was going on around them, I would, hypothetically, ask once or twice more, maybe in a different way or at a slightly different time, so they might catch their error, or give me a clue how to prompt them to catch their error. Hypothetically, I wouldn't just escalate things by telling them directly they're giving me a bad position. Hypothetically, I might just be confirming the lat/long I've already derived by other means to make sure I'm not chasing ghosts and I'm headed straight towards them, rather than to a bogus position or false contact, then trying again.
 
quote:
Originally posted by Billylll

Any boat that pushes the emergency DSC automatically shows the boat in distress on my plotter.
From there it's easy for me to see if I can render assistance.
This assumes they have the DSC GPS data properly talking to their VHF radio.
Bill

Click to expand...


I believe your boat has a direct line to NSA to intercept the click of their microphone. For the rest of us landmarks help. :D
 
Some Chesapeake charts are in D-M-S and some are D-M.mmm. So send the position in whatever is quickest. As a comms watchstander, I know we all know how to do the conversion, usually in our heads. Just don't send LORAN TDs. One of the local waterman asked if that was OK. Hook those two wires from your GPS to your radio, and get your MMSI. Then push the red button on your radio when you need help. Let Rescue 21 do it's job.
 
quote:

quote:
Originally posted by Billylll

Any boat that pushes the emergency DSC automatically shows the boat in distress on my plotter.
From there it's easy for me to see if I can render assistance.
This assumes they have the DSC GPS data properly talking to their VHF radio.
Bill

I believe your boat has a direct line to NSA to intercept the click of their microphone. For the rest of us landmarks help.

Click to expand...


Bill is NSA
 
quote:
Originally posted by pdecat

quote:

quote:
Originally posted by Billylll

Any boat that pushes the emergency DSC automatically shows the boat in distress on my plotter.
From there it's easy for me to see if I can render assistance.
This assumes they have the DSC GPS data properly talking to their VHF radio.
Bill

I believe your boat has a direct line to NSA to intercept the click of their microphone. For the rest of us landmarks help.

Click to expand...


Bill is NSA

Click to expand...


That's the only thing that explains the antenna farm on his boat.
 
N/C Mike- Curious, does the Rescue 21 received-VHF-transmission positioning data automatically get displayed on your vessel in near real time if you are in the appropriate response area (& if DSC interfaced to GPS was not used) , or does that have to be purposely sent from the Group station? I'd think very weak reception could still limit effectiveness of Rescue 21 too, but that system sure sounds like a wonderful tool. Is rescue 21 as fully implemented nationwide as planned or is it still expanding?
If any of that is not for public discussion, please disregard.

Bill- Sorry to momentarily sidetrack from your question.
 
I have to disagree with some of the above. Voice is a critical communications component, from Mayday on down. And the only thing that should be used in less-then-Mayday situations. So knowing how to give and understand a position accurately is an essential mariner's skill. Merely flipping your DSC switch and activating your EPIRB starts a big guessing game. What is the nature of the distress? What resources and equipment is needed to mitigate that distress? I have heard many situations where another boat was acting as a relay for the boat in distress. One I recall readily was a real CF where the relay boat, with all good intentions, was having difficulty giving the CG good info. The CG finally calmed the guy down and said " Captain, I want you to ask them this exactly_____" In another both the distress vessel and the relay were really superb at communicating all the right information, in that case someone who was having a heart attack. Saved the guys life.
 
No guessing games when properly programmed George. How about -0- guessing games the only people that would be guessing would be those whose systems are not DSC compliant and EPIRB's are registered every 2 years or if any changes are made to the contact information or the vessel.
So I guess if someone pushes the emergency DSC and has no data talking to the radio and if their EPIRB (406) information is outdated then you would be correct. I'd rather deal with the on hand emergency after I have hit all the correctly programmed devices distress functions and talk when I am able to or let my wife do the talking.
I have responded and rendered assistance to more than one distress call while out cruising. The easiest to find are boats/ships with their DSC properly programmed. In addition the new AIS MOB devices will probably also help me locate a person in the water once this starts getting used by more mainstream boaters.
Voice comms are good but too many people get excited and scream into the mike making the readability quite poor, on the other hand good or proper data in = a quick timely accurate track to the location for vessels responding if your so equipped. Every USCG boat, most US Boats and SeaTow boats have the proper equipment to locate a properly initiated DSC emergency call most modern boaters also have similar equipment.
In fact with my FLIR if I heard or saw a MOB call go out within 5 miles of my anchorage or dock I would respond at night. I stand a good chance of finding the thermal image of a MOB if I have the proper position reported directly to my network.
Bill
 
I have been in Block Island where there were 1000 boats anchored/moored. I would hear people calling on the VHF for the launch to pick them up. When asked where they were, they would say, "near the white sailboat with the flag on the stern"...
 
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