user updated mapping... color me confused!

[OkobojiEagle]

Navionics+ (and probably other maps as well) allows downloading updates to a lake map taken from individual users of the map.  Considering GPS isn't "to the inch" accurate and lake levels change, how is the accuracy of these maps improving?  

 

oe

[OkobojiEagle]

Found my answers on another site... thanks.

 

 

oe

[Wayne P.]

I hope your search included the accuracy is only as good as the data collected and how much interpolation is involved in creating the contour lines.

 

Some don't set their equipment up so they can get accurate data:

GPS antenna where the transducer is and depth offset to allow for transducer depth.

[OkobojiEagle]

I don't think what I found (or understood) was that in-depth.  What I do understand (I think) is Navionics uses a separate layer for community data and doesn't change their base layer of chart info.  It probably isn't going to matter to me, as I'm looking to use the map to store personal way points from my local lakes and not much else.  I won't be uploading any of my data (as if I could figure out how anyway) or, most likely, downloading any changes to the map after I have it loaded into the Hook 7 sonar.  I'm looking to purchase the Navionics+ card, if there is a better map suggestion for the Hook 7 please post it this evening as I'm off to make my purchase tomorrow.  I'm not counting on finding knowledgeable sales help at the Cabelas store which is 7 hours away.  As always, I appreciate the information this board provides me!

 

oe 

[Wayne P.]

Sonar Charts is what the user generated maps are called. It is a separate map from their Nautical Charts. If is viewed by selecting FishNChip.

 

Navionics does change their base map if the uploaded data conflicts with land. They will re-draw or create the whole shoreline if the data is shown crossing land where their base map is incorrect.

All the waters I have done have been that way.

 

They also add some of their details to the Sonar Chart map layer such as bouys, creek channel highlighting, some notes.

 

You don't store waypoints on a map card, waypoints are written to the unit's memory. You can have waypoints, routes, and trails with no background mapping--that is GPS data, not map data.

 

Navionics+ is available in two versions.

16GB Navionics+ Preloaded---$199

Navionics+ Regional---$149

[OkobojiEagle]

Thank you Wayne.  Even the smallest flicker of candle light is helpful when I'm navigating in total darkness...  your explanation is once again illuminating.  

 

My original intent was to replace my grey scale screen Lowrance X-85 unit with a similar color screen unit.  I've bit off a tad more with the Hook 7 and its apparent I've got plenty of chewing to do before I get this unit thoroughly swallowed.  Thanks again for the helpful information.

 

oe

[Further North]

5 hours ago, Wayne P. said:

GPS antenna where the transducer is and depth offset to allow for transducer depth.

I feel like this is a much bigger deal than I see discussed very often...and it's one of the reasons I am still not a fan of fish finders with internal GPS.

 

My boat still has two external GPS pucks, one as close to the trolling motor shaft as I can get it, the other tight to the inside of the transom and dead center over the transducer.

 

That said, with SI and 360° I can get where I need to be.

[Wayne P.]

1 hour ago, Further North said:

I feel like this is a much bigger deal than I see discussed very often...and it's one of the reasons I am still not a fan of fish finders with internal GPS.

 

My boat still has two external GPS pucks, one as close to the trolling motor shaft as I can get it, the other tight to the inside of the transom and dead center over the transducer.

 

That said, with SI and 360° I can get where I need to be.

 

Internal GPS is great for a bow unit for contour mapping and creating/returning to waypoints since that is where the transducer would normally be with a proper installation= less rigging.

 

I have done three lakes with Sonar Charts that are electric-only using a bow mounted unit with transducer on the bow trolling motor.

[Further North]

1 minute ago, Wayne P. said:

Internal GPS is great for a bow unit for contour mapping and creating/returning to waypoints since that is where the transducer would normally be with a proper installation= less rigging.

I would have been OK with that, but the first unit I mounted up there was an 1197, so I left the puck in place.

 

[Wayne P.]

Good choice. I have a AS GPS HS antenna at my bow for another reason, so I can do either.