Topic: GPS view 180 degrees out

[ChrisC]

I just installed a used 798c on my boat and will be headed for the Keys in the morning and have been testing and putting way points in.
When I toggle to the GPS view it is showing 180 degrees out. (boat and unit facing south unit says north) and I am in the course direction to top.

What should I be checking, Thanks for any help for the new guy.

Chris C.

[George]

ChrisC

On navigation do you have North up or Course Up?  This is probably the issue.  North up will always have the chart North Up.  I normally keep mine at course up, I identify better with contours on the charts with course up.

George

[ChrisC]

My settings are course up

[ChrisC]

See Picture

[George]

ChrisC

The only choices are North Up and Course Up.

From looking at your picture, I noticed that you are only moving at a rate of 0.2 mph.  What does it show when you are moving at a faster rate on a steady course?

If I turn my unit on while the boat is stationary on the trailer and look at the chart the boat over time appears to move in multiple directions and speeds change even though it is not moving, the GPS is constantly and adding and dropping satellites.   This (I think) gives the appearance of moving even though it is stationary.

The only other thing is there any interference for you compass have you tried removing the unit to determine if the compass reading changes?

These are the only things that I can think of, maybe someone else has some ideas.

George

 

[ChrisC]

Boat is in my driveway at the moment, Does it need to be moving to be orientated?
And when I plot a course for the eagle wreck it says 652 miles but points north.

[George]

ChrisC

Yes the boat needs to be moving to be oriented.  The unit does not have an internal compass, it uses the GPS signals when moving to show course direction. 

If you turn on your unit while in the driveway, with the navigation maps showing and leave it on for an hour you will observe a track which will go in multiple directions, the longer the time the more movement.  There is an example of movement comparing 3 GPS pucks.  The pictures I believe are over a 24 hour period in a stationary position.

This link will will take your there, hope this helps, go to the top of the page.

>>> http://forums.sideimagingsoft.com/index.php?topic=229.msg739#msg739 <<<

George

[ChrisC]

Thank you very much.

[ChrisC]

Well that is not it, I towed it to put gas init about 7 miles and it was 180 out the whole time.??

[ChrisC]

One more up date, the boat is now parked in the street 90 degrees off from drive way and GPS graph is now 90 degrees off.
So what is more accurate is the little red boat on the graph is always pointing north and north is always on top.

Unit is set for  Course at top.

[George]

ChrisC

Everything you have set will be fine, you must have the boat on the water and moving forward to get the course direction and the boat pointing in the same direction as the course. 

George

[Humminbird_Greg]

George is right.  Once the boat stops detecting direction, it will default to showing the boat and map in a north up orientation even though the menu setting is Course-Up.  When the boat stops the unit does not remember what direction it was moving.

[ChrisC]

10/4 and thank you, I will be in Islamorada in the morning so we shall see.
But it makes cense.

[sonar2000]

Just for this reason it is a good idea to have a compass on the boat in addition to your GPS...At least you will always know which direction you are going or heading and even when sitting still..

Chuck

[ChrisC]

Well once in the water and moving I could not be more pleased, But I have two questions.
1) Is it possible to disable tracks? Hoping from reef to reef it starts to look like spaghetti.
2) when in chart view is it possible to set it where the direction to the waypoint moves with the boats location, If I take a detour all it does is nag me about being off course. unless I reset and start over.

[Humminbird_Greg]

 1) Yes it is with current software.  There should be a “Stop Tracking” option in the “Current Track” menu (found under the “Nav” menu tab).

 2) No, not if you are following a route to that waypoint (using the “GOTO” button/function creates a temporary route and waypoint if needed). The unit assumes a straight line route between where you are and the location you want to go to.  You can set a route up that would take you around islands.  You can of course turn off the Off Course Alarm and you will not see or hear the off course message/alarm.  As an alternative you could place the cursor over the location you want to go to and just use the bearing and distance information to get there.

[ChrisC]

Thank you Greg, I need to update firmware the "no tracks" option is not there.