Do added maps replace the basemap, or add to it?

[+Kohavis]

Pardon my newbie question, but my first ever GPS unit is on the way. In the meantime I've been reading up on additional maps that are available, like Mapsource TOPO US 2008, Metroguide and City Navigator.

 

I'm thoroughly confused now.

 

The unit on the way is a Garmin eTrex Venture HC. It says it has a basemap. Is that available for real-time tracking mode (have the streets scroll past on the screen while the cursor remains centered)?

 

And if I load additional maps, do they merely augment the existing map?

 

What I'm looking for is a real-time display for when I'm using the GPSr for other than geocaching. Like a road trip we're planning. I figured I could use Mapsource to design and then download just the maps from my planned route to the unit, using the available 24MB memory the unit has. But if the unit already has a basemap, what's the point of adding maps? Garmin claims that the basemap can't be removed or replaced.

 

I'm completely confused. Could a resident GPS sage help me out with this?

 

Thanks

[+RRLover]

The added maps supplement the base map. If loading maps from both map applications to the

handheld through MapSource, do so at the same time. As anytime you reconnect to add maps,

the new upload overwrites the existing 'supplemental' maps. That is if you want both Topo, and

CityNav on the receiver at the same time.

 

Norm

Edited September 5, 2008 by RRLover

[+Kohavis]

Thanks for the help RRLover.

 

Maybe my question was confusing. My main question is: What exactly does the supplemental map add that the basemap doesn't already have? Is it greater detail/accuracy, more features, etc.?

[MtnHermit]

The base map has major roads, think US Hwy and greater, and major cities, nothing more. It's primary purpose is to position you via those objects so when you drill into a detail map you start in the correct place.

 

City Navigator has street address detail and routing, the map plus the GPS will calculate a point to point route, across town or across the country.

 

Topo 2008 adds contours and more water feature details, but no street addresses or routing.

 

FWIW, strongly advise you return your HC and get an HCx. The "x" signifies a microSD memory card so that you can hold an entire state's maps at 24K detail. An HC has a pitiful amount of memory.

[+trainlove]

The way it is on a Magellan is that the Detail maps go 'on top' of the basemaps in a seamless manner.

 

That is probably how it is done for Garmin since the Garmin programmers are 500% better than Magellan hacks.

 

You will see the basemap when you are zoomed out to perhaps 0.8 mile scale, and the detail maps when you zoom in closer. It doesn't seem to matter what you have for map setting (highest, high, medium, low, lowest)

 

RT101 in New Hampshire is a prime example of a really bad basemap. You seem to be driving 5 miles from any major road at spots. But when you zoom in you are on the road. It appears that there is confusion between the interstate and the state road .

[+Kohavis]

Great. This is exactly the info I needed. Thanks!

 

As far as returning the unit, at least let me outgrow it first I don't want to spend a fortune on the GPSr, and there's a considerable price jump when you go to the "X" models. I wanted a unit that I wouldn't outgrow in a year (I was also considering the Legend (No H, C or X at the end of the model name), and decided on this one because it wasn't much more money than the 7-year-old Legend.

 

But at the same time, if I lose interest in geocaching in three months, I'll kick myself for plunking down $250 - $300 for a GPS unit that sits in the drawer, or ends up going for 40% of its new price on E-Bay. That's also the reason why I'm still only a regular member. If I stay as interested as I am now, I'll have no problem signing up here for a year. But I need a few more caches, and a little more time before I'm willing to make that commitment.

 

But the GPS unit is arriving in the next few days, and I already have 5 caches made up, just waiting to be placed Once I'm "armed", I'm sure that many residents of this area will wonder who that guy with the red baseball cap is, and why is he pacing around their front yard? I fully expect to be a regular fixture here for some time to come.

 

A week ago I found my first cache when my sister (Dittersfeet here) visited from out of town, She took me out for my initiation, we found four caches and the first of aonther two-stage, and I'll tell you ...I was immediately hooked. It reminded me of my dad and how he planted riddle clues all over the house so us kids would have to work for our Easter baskets