Help w/ Humminbird Marine GPS unit

[DaveC426913]

Anyone here into sailing or boating?

I haven't left my mooring yet, been testing it at anchor but my new Humminbird 383 insists I'm pointing NE when I'm actually pointing SW.

It changes its mind every so often, occasionally it's correct, but seems to return to this position. I've left it for a half hour or more. I've tried hand-holding it and turning it, doesn't seem to register the rotation.

Am I missing something? Is there a configuration I need to go through? (For a while, I wondered if there was a flip northern/southern hemisphere setting or somesuch)I haven't left my mooring yet, been testing it at anchor but my new Humminbird 383 insists I'm pointing NE when I'm actually pointing SW.

It changes its mind every so often, occasionally it's correct, but seems to return to this position. I've left it for a half hour or more. I've tried hand-holding it and turning it, doesn't seem to register the rotation.

Am I missing something? Is there a configuration I need to go through? (For a while, I wondered if there was a flip northern/southern hemisphere setting or somesuch) Does it need a milk-run to get its bearings? (Years go, my car compass wanted me to drive in circles until it locked on North.)


I've checked the GPS satellite display; it seems to be receiving several. There's nothing in the manual.

 

[DaveC426913]

Never mind. Mystery solved.

As soon as we started moving, it immediately knew which way we were pointed. And, the moment we stopped again, it lost track of our orientation.


Conclusion: A GPS device does not determine one's orientation by determining the orientation of the device itself; it determines one's orientation by determining one's movement and then assuming one's orientation is pointed in the direction of movement.

i.e. if you're not moving, you have no orientation.
Also, if you are under power decide to throw it into reverse, presumably the unit will show your orientation as rearward.