SIGforum
Lets talk coordinates

This topic can be found at:
https://sigforum.com/eve/forums/a/tpc/f/320601935/m/5120086225

October 30, 2026, 04:52 PM
CPD SIG
Lets talk coordinates
quote:
Originally posted by arabiancowboy:
MGRS + HAE elevation if you want an exact spot on the parts of our earth most people use.

Question for anyone who uses underwater coordinates: is depth measured exclusively off MSL or are other paradigms used as we do with height?


While employed by our favorite uncle, MGRS and Depth gauge.
You’re also taught lat & long and depth. You become fluent in both.
Then you have the fun and enjoyment of learning knots, nautical miles, miles, kilometers.
Just when that shit didn’t scramble your egg enough, you had feet and fathoms (1 fathom = 6 feet).
Civilian side of the house, it’s Lat & Lon- depth is in feet. (Salvage diving)

Pay attention to the legend on the map, it will tell you what system of measurement you’re using.
x————-x = 1km - you’re using the metric system
X—————x = 1mi - you’re using the system that puts people on the moon
X—————x = 1Nm - damn Navy.

There’s also toppo maps of the sea floor that are *** relatively accurate *** from hydrographic surveys.
I use *** relatively accurate *** because due to tides and storms, the sea floor shifts.
Using a 10 year old map, that sand bar in the middle of the channel WAS 3 feet below the surface, and 15 yards long.
Today, it may be an island, or it may be gone.


______________________________________________________________________
"When its time to shoot, shoot. Dont talk!"

“What the government is good at is collecting taxes, taking away your freedoms and killing people. It’s not good at much else.” —Author Tom Clancy
October 30, 2026, 04:57 PM
parabellum

October 30, 2026, 05:10 PM
trapper189
+90, 0-360
-90, 0-360

polar coordinates
October 30, 2026, 05:12 PM
parabellum
quote:
Originally posted by trapper189:
polar coordinates
The Arctic. The Antarctic.
October 30, 2026, 06:32 PM
old rugged cross
Thanks guys, spwamike that was kind of what I was asking.



"Practice like you want to play in the game"
October 30, 2026, 07:29 PM
smlsig
quote:
Originally posted by SPWAMike0317:
PA State Parks make good use of coordinates. Here is an example from the website of my favorite park:

From I-76, take Exit 110 (Somerset) and drive west on PA 31 from Somerset for eight miles. Turn left onto Trent Road and follow the directional signs to Laurel Hill State Park.

The park may also be reached from Exit 91 (Donegal) of I-76 by turning left on PA 31 east and traveling 14 miles. Turn right onto Trent Road and follow directional signs to the park.

GPS DD: Lat. 40.01023 Long. -79.2244

This is how to read the coordinates.

• First number (Latitude): Measures north (+) or south (-) from the Equator (between -90 and 90).
• Second number (Longitude): Measures east (+) or west (-) from the Prime Meridian (between -180 and 180).
• Order rule: Always latitude first, longitude second.

This is how it would look when entering into something like Google Maps or a Garmin GPS: 40.01023,-79.2244

There are converters that change digital coordinates to Degrees, Minutes, Seconds so they look like this: N 40° 0' 36.828'' W 79° 13' 27.84''. This is handy for paper maps and charts (remember those?)

If you "drop a pin" in Google Maps, the digital coordinates can be copied and shared. Mighty handy if one needs emergency assistance.


When using a decimal GPS coordinate the question is how many decimal places do you use, or how accurate do you want to be? Some people go to 8 places…

On the other hand there is a free and very simple app to use called “ What Three Words” that has decided the complete planet into 10’ by 10’ squares. It is very intuitive to use and can be exported to Google Maps to navigate to virtually any point on earth. The NPS is using it particularly in SAR.


------------------
Eddie

Our Founding Fathers were men who understood that the right thing is not necessarily the written thing. -kkina
October 30, 2026, 07:49 PM
Pipe Smoker
quote:
Originally posted by parabellum:
quote:
Originally posted by trapper189:
polar coordinates
The Arctic. The Antarctic.

That’s the way I feel about ’em too!


Serious about crackers.
October 31, 2026, 06:49 AM
trapper189
North and South Poles. An infinite number of lines of longitude meet at the poles.
October 31, 2026, 12:43 PM
ftttu
My 5th grade teacher gave us a way to remember longitude and latitude lines. She said, “When you launch something, it goes up, so just think “launchitude.” That has always worked for me.


Retired Texas Lawman
October 31, 2026, 12:50 PM
Gustofer
^^^^ Flatitude was how I learned it.


________________________________________________________
It is long past time for a Convention of States. The Founding Fathers gave us this tool to fix an out of control government and we need to use it.
October 31, 2026, 01:24 PM
selogic
Thank GOD I have no use for anything other than a street address.
October 31, 2026, 01:40 PM
Redleg06
See Chapter 4 of FM 3-25.26. You can download a free copy here...
https://archive.org/details/Fm...INGANDLANDNAVIGATION


"Cedat Fortuna Peritis"