Dennis Pogson wrote:
Roger Long wrote:
"Dennis Pogson" wrote

One tip Roger. When selecting charts to upload to the unit, you may
overlook
the fact that some larger area charts contain smaller area charts,
ie the same area is covered on 2 or more charts, but be aware that
the detail contained in the small area chart can be substantially
greater than that contained in the large area chart, so that zooming
in to a large area chart
does not give you the same amount of detail as using the smaller
area chart.


Are you saying that, if you have both charts loaded and active and
zoom in, the unit will give priority to the large scale chart and
suddenly present you with no detail as you sail into a bay or harbor?
This is a very important point because it could lead to loss of a
boat and life in a high stress situation. Having to suddenly go back
into set up and turn off the large scale chart just as I'm entering a
harbor would probably be enough to lead me to Ebay the whole thing.
I'll check this on mine but I'd appreciate your (or other Garmin
user) clarifiying as these kinds of operation are not always
consistent.

The road / chart conflict I know about. That's why I'm segregating
road and marine data on two separate data cards.

No, I am saying that if you load the large-scale chart, but miss out
the smaller-scale chart, you will have only the detail which is
included on the large-scale chart, so either load both, or just the
small-scale charts. The Garmin always seems to seek out the chart
with the greatest detail when you zoom in. These smaller charts do
not always overlap anyhow, so you are best to load the large-scale
charts as well as the small-scale ones. If you find yourself in an
area not covered by a small-scale chart, you will know, because as
you zoom in, you lose detail.

Roger,

Have just re-read my last post.

Please substitute the word "area" for the word "scale" in my previous post.
Small-scale charts cover a LARGE area and large-scale charts cover a SMALL
area!

You would think I'd been navigating for 2 weeks instead of 45 years, the old
brainbox must be suffering from all this global warming!

Dennis.