Lat Long

[Chris 69]

Hi guys and girls, im new to this can you help?
My home port is 54.16.879 N 0.23.374.W.
Putting that in my garmin gps, it only gives me 2 spaces on the last set of numbers.
For example on the lat it is 879 N. And long 374W.
Do I put 87 and 37 respectively.
Hope you can help.

[Mike OReilly]

So you’re reading the coordinates from a one source, and you want to plug it into a different GPS unit (Garmin) to create a waypoint? Couldn’t you use the Garmin’s browse system to generate the coordinate?

In any case, I’d simply apply normal rounding to the number; so “88” and “37”. Two significant digits for fraction of degrees (seconds) is plenty accurate.

[redhead]

Personally, I would round up or down on the seconds. That should get you as close as Garmin wants you! Welcome, by the way!

[delmarrey]

One second is equal to 80 - 100 ft respectively. Like redhead says. Round it up/down.

[Mirage35]

That appears to be the point of the breakwater - better to go just a teeny bit further west.

[El Pinguino]

What they are saying ^^^^^^^

I am assuming we are talking decimal minutes here and not seconds of arc. In which case write it as 54*16'.879 N , not 54.16.879 N ( I use * for 'degrees' on the puter... to much fuss making a proper 'degree' symbol )



Let's consider latitude first.....1 minute of arc is 1 nautical mile .... the first decimal place is 170 metres.... the second decimal place is 17 metres.... the third decimal place is 1.7 metres..... which end of the boat are we talking about here ?

With longitude the numbers are smaller still esp in your latitude.

In the ocean whole minutes are all you need, coastal navigation use the first decimal place. Only in logging narrow passes, anchorages and harbour features do you need to bother with the second decimal place. The use of the 3rd decimal place shows a lack uf understanding of what you are working with..

[Chris 69]

Thanks guys I now understand it, wish I'd posted earlier, could have saved on the reading.

[32irwinSWFl]

I would look online for a Lat/Long converter. We had an issue offshore one stormy night, called USCG and read our Lat/Long off the GPS, and they kept saying we were off of Venice beach area, when we were 12 miles off shore straight west of Red Fish Pass,,,they eventually used the Bat21 (not sure of name) and determined we were off Red fish pass,,,,so be careful about reading GPS numbers,,,,there are at least 3 different formats used...Very Very confusing....