Humminbird Side Imaging Forums
Side Imaging Forums => 798c SI => Topic started by: wishn i was fishn on May 12, 2012, 08:06:04 AM
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I have had my 798 for about a year and a half now. I recently have come across some gps coordinates that I wanted to manually enter. After entering about 25 waypoints and reviewing them, I realized that the actual location was way off of the desired location, as I have an aerial photo to refenece. I also entered them into a handheld and those waypoints are correct.
It seems that the newly created waypoints are nearly 1/4 off. How do I correct this?
If I cursor approximately over the desired location the coords are way off, to the actual coords.
Also when entering waypoints my 798 will only allow me to enter 7 digits instead of 8 like many others. Why is that?
example humminbird 39 06 49.0
others 39 06 49.00
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Just make sure that you are using the same Datum (WGS84 or others) that match the paper map or aerial photo with what the unit is setuped for.
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There should be an option under your Waypoint menu for
the format type of the coordinates.
There are 4 or 5 different types, so you may
not be keying them in correctly.
??.????? degrees is the most accurate format.
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The Position Format menu is under the Setup menu tab.
You are correct in that the dd.ddddd menu setting is the most accurate.
The waypoint example you posted wishn looks to be in the Degrees Minutes Seconds format. Some allow the addition of decimal seconds but so far Humminbird has not. This has been asked for but has not been changed.
As for the waypoints being off: are they off according to the map that is being displayed on the unit or are they off because you have actually traveled to these places? I ask because the map may be off for the lake that you are looking at – which is a separate thing than the actual waypoint being off. You do need to make sure that you are using the same Map Datum and coordinate format but this is another reason why the waypoints could look off but be accurate.