Waypoint Position Changing Internally

[reeldetermined]

I have a1944c, Navnet vx2. system update 195002404.03.07. C map chart dated 6/2018.

I recently plotted a course to an area I'm not familiar with.
I took my positions from USCG, Light List: Due to this area changes constantly.
https://www.navcen.uscg.gov/pdf/lightLi ... hanges.pdf

29160 40.37.453 N, 73.17.439 W
My settings are: DD.MM.SS.S
I manually input these coordinates and save the waypoint, select Go To Waypoint the system converts the entered waypoint data to:
40.37.27.2N
73.17.26.3W
This is a point on land!
I go to: waypoint list check data entry, it appears to be saved correctly in the waypoint lis,
again enter Go To Waypoint sends to the way point in the converted position, which is on land.

This has happened with several waypoints!!!!

I have called the tech line several times.
No one can help.
How do I solve this problem?

 

[C-Bass]

Good afternoon Reeldetermined,

I believe I found out what is going on. The points listed from the USCG document is using a L/L format: DD.MM.SS.S or Degrees, Minutes, Seconds.

Here is where it gets a little tricky, the NavNet Vx2 has some limitations. It will allow you to display L/L format in DD.MM.SS.S. However, when you enter a waypoint numerically it only gives you one choice to enter the waypoint format and that is DD.MM.MMM which is Degrees and Decimal Minutes. So if you try to enter the waypoint using DD.MM.SS.S it will only allow you to use DD.MM.MMM so the point will be off if it is not converted first.

You will need to convert the point from DD.MM.SS.S into DD.MM.MMM. For your example the point #29160 is referenced as: 40-37-45.279N, 073-17-43.955W by the document.


If you convert that point into Degrees and Decimal Minutes it will be:
DD.MM.MMM: 40-37.755'' N
DD.MM.MMM: 73-17.733' W

I believe that is what is happening, it is a conversion thing. Although you can display Degrees, Minutes, Seconds the only format to input waypoints is Degrees and Decimal Minutes.

Kind Regards,
C-Bass

 

[OldIronsides]

C-Bass is correct on this. The VX2 will not allow you to enter a new waypoint in any format other then DD° MM.mmm. All of these waypoints you have will need to be converted into this format first before being entered.

I have run across this in the past, that is precisely what is happening.

 

[reeldetermined]

I realize the system is converting the input numbers.
How do I do this conversion?
Hopefully tomorrow I will manually input: DD.MM.MMM: 40-37.755'' N
DD.MM.MMM: 73-17.733' W
Upon entering this data I will see where this point is plotted.

 

[C-Bass]

Good evening Reeldetermined,

You can use the following to convert from Degrees, Minutes, Seconds to Decimal Degrees.

To convert 40º 05’ 18” N to degrees and decimal minutes do the following:

We are converting the seconds to a decimal part of a minute

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
18/60 = 0.3
Add the decimal minutes to the minutes and “discard” the seconds
05 + 0.3 = 5.3
So the answer is 40º 05.3’ N

Or you can use google and find a L/L conversion calculator.

https://www.directionsmag.com/site/latlong-converter/

Kind Regards,

 

[reeldetermined]

I went to the boat today, started the system, did the conversion and it worked!
Which is great.
Thank You ALL!!!
This is a learning process.
I realize that old school Lat/Lon positioning is different than GPS positioning.
I apologize for the terminology incorrectness.
What I do not understand is The system has 4 input selections.
DD.MM.MM'
DD.MM.MMM'
DD.MM.MMMM'
DD.MM.SS.S''
Upon taking a true Lat./Lon position and doing the correction for the seconds, entering the waypoint. What do the 4 listed inputs have to due with the correction?

Again Many Thanks!