When you put in numbers with 6 digits and gps unit has room for 7 digits do you just leave the last number blank? I found some old numbers from many years ago and they are only 6 digits,can’t remember what I did in the place for the 7th number. Thanks
I’d just put in a zero and it will probably work. If you want to be sure though, you could always share the numbers with me and I could verify their accuracy 
Six numbers gets you close but not on the spot. You’ll have to do a little recon to find the spot.
Olde Man Charters
Check out the table below (link is also there for convenience). It gives a quantitative scale of what you get by adding digits…
https://en.wikipedia.org/wiki/Decimal_degrees
Put in as many numbers as your unit will process. I can put at least 10 numbers into my Garmin, but it only computes to 3 decimals … 
That chart above is NOT the common GPS format by which most fisherman share numbers… The chart above shows:
DDD.DDDDD (“Decimal Degrees”)
DDD MM SS.SSS ("Degrees, Minutes, Seconds and fractional seconds)
The most common format among fishermen is:
DDD MM.MMM (“Degrees, Minutes and fractional minutes”)
So, when someone says “6 digits”, it depends on what format you are using…
1 degree of latitude is 60 nm. 1 degree of latitude can be broken down into 60 minutes. So, each minute = 1 mile… Thus, the distance between 32 33.000 and 32 34.000 (in DD MM.MMM format) is 1 mile…
1 nautical mile = 6076 ft.
6076 x 0.1 = 607.6 ft
6076 x 0.01 = 60.76 ft
6076 x 0.001 = 6.076 ft
So, the first question is: What format are you using?
Glad to hear there’s a standard. I know I have maps with 2 of the 3 =/ There are sites that will do the conversion, or you can do it in Excel/etc. Either way, you’re right, getting the format right is critically important.
quote:All GPS will do the conversion too... Just need to know what your GPS is set up for... I'm pretty sure that DD MM.MMM is the default on most GPS, but usually not that way for something like Google Earth...
Originally posted by uarussGlad to hear there’s a standard. I know I have maps with 2 of the 3 =/ There are sites that will do the conversion, or you can do it in Excel/etc. Either way, you’re right, getting the format right is critically important.
Good information here… thanks.
Capt. Jim
26’ Ranger CC (Offshore)
Twin 200 Yamis
How would one take the Maps Uniques numbers and enter them into ones Garmin?
I don’ have one with me currently, but I believe the Maps Unique charts are formatted like 32.7317 -79.8584, right? If so, I think they are in the correct format and you can just manually punch them in. You’ll know pretty quick if it’s the wrong format. However, that manual process can take a while. Assuming your unit has an SD card slot (likely micro-SD card), you may be better off using your computer…
Here’s what I do: Type the ones you want in excel (or the free Google Docs spreadsheet program) and save in CSV format (comma-separated). The CSV file should be formatted as Latitude,Longitude,Name (3 columns) and each row is a different waypoint. Then use a free application called GPSBabel to convert to GPX format that Garmin can read. Then you take your micro-SD card, plug it in to your Garmin, and copy over the waypoints.
One note, you may want to backup your Garmin to your micro-SD card first, in case you accidentally overwrite everything (highly recommended). The cool thing, is once you get familiar with the process (it can be tedious), it’s easy to download info from your Garmin, view on Google Earth/etc. It’s also easy to save/reload all waypoints as necessary. Just go slow and make a backup of your Garmin before you start (maybe make 2 if you have 2 SD cards… you can get them cheap at Amazon/Wal-Mart/etc… they don’t need much capacity).
You can also buy the MapsUnique data on CD if you want to load everything into your GPS (~$200). I’m sure some on here have experience with that, but it might be overkill depending on how often you get out. Good luck!
Here’s a link to a method to do any conversion. I copied the text below, but it renders poorly. Finally, I found my excel sheet that does the conversion. PM me if you want a copy. Obviously, no warranty, use at your own risk, not responsible if you end up on the rocks…
How to convert among the three different forms of Latitude and Longitude
This document outlines how to manually convert among degrees minutes seconds, degrees and decimal minutes and decimal degrees:
To convert from degrees minutes and seconds to degrees and decimal minutes
• Divide the number of seconds by 60 and add that value to the number of minutes – do not change the number of whole degrees
• Example
o To convert 40º 05’ 18” N to degrees and decimal minutes do the following
#61607; We are converting the seconds to a decimal part of a minute
#61607; Divide the seconds (18) by the number of seconds in a minute (60) this will give the decimal part of a minute that 18 seconds represents
#61607; 18/60 = 0.3
#61607; Add the decimal minutes to the minutes and “discard” the seconds
#61607; 05 + 0.3 = 5.3
#61607; So the answer is 40º 05.3’ N
To convert from degrees and decimal minutes to decimal degrees
• Divide the number of minutes by 60 and add that value to the number of degrees – do not change the number of whole degrees
• Example
o To convert 40º 05.3’ N to decimal degrees do the following
#61607; We are converting the minutes to a decimal part of a degree
#61607; Divide the minutes (5.3) by the number of minutes in a degree (60) this will give the decimal part of a degree that 5.3 minutes represents
#61607; 5.3/60 = 0.08833
#61607; Add the decimal d
Dang, y’all make it sound so complicated
There are 60 mins in a degree and 60 seconds in a minute. If you can’t figure it out from there, you stink at math.
quote:
Originally posted by jwsDang, y’all make it sound so complicated
There are 60 mins in a degree and 60 seconds in a minute. If you can’t figure it out from there, you stink at math.
haha my head is spinning 
You guys are a wealth of knowledge, much appreciated !
Thanks for the email!
quote:Trouble is, 90% of fisherman's GPSs are not set up for seconds... Also, mins and seconds do not tell you anything about distance. 1 minute of latitude is = 1 nm, but not so for longitude, since a minute of longitude gets shorter as you get closer to the poles...
Originally posted by jwsDang, y’all make it sound so complicated
There are 60 mins in a degree and 60 seconds in a minute. If you can’t figure it out from there, you stink at math.
Make it as simple as possible, but not simpler.
quote:
Originally posted by Marsh-pickerWhen you put in numbers with 6 digits and gps unit has room for 7 digits do you just leave the last number blank? I found some old numbers from many years ago and they are only 6 digits,can’t remember what I did in the place for the 7th number. Thanks
You can’t catch fish on a dry line
If your unit uses decimal degrees (DDD.dddddd) then 6 decimal places is about 1 meter accuracy which is more than practical on the ocean. Even only 5 decimal places gives you 10 meter accuracy. Realistically, either one is perfectly fine considering that your anchor swing is always going to be far more than 10 meters.
As others have stated, make sure that you know the difference between decimal degrees (modern standard for GIS and surveying data), and degrees with decimal minutes (DD MM.mmm) which (unfortunately) many marine GPS’s still default to.