Wayne.B wrote:
On Wed, 04 Jan 2006 22:23:15 GMT, Gary wrote:


CMAP and all the other proprietary stuff. The NOAA products are
warranteed, correctable and verifiable. The rest are just eye candy.


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That's a bit harsh in my opinion. Both the CMAP and NOAA products
serve a useful purpose. I have both. I've never found an error on
one of my CMAP charts that is not also on the NOAA product. Chart
errors are just a fact of life around here in south Florida but I've
been the entire length of the east coast this year, and back, with no
issues regarding CMAP charts. In many cases the CMAP charts were more
up to date than my somewhat older BSB/raster collection (NOAA images).

Well you are lucky and wrong. CMAP, which I use every day on a Furuno
chart plotter, compared to real charts which I actually navigate on
every day is vastly different. It is very evident that the chart work
is done by geeks as opposed to cartographers. The single most commen
error that I see is when the cartographer marks the bottom with an R
indicatig a rocky bottom and the CMAP gek puts a rock there. Within 10
mile of where I live I can show you a dozen without trying. I even
talked to the vendors about it and they said they only do updates once
in a while and that stuff wasn't critical.

All CMAP is really good for is seeing where you are at a glance. You
can bet the bulk carriers full of some toxic sh*t aren't using CMAP to
find there way up the creek. In fact nobody but yachties us it because
they are the only folks who will trust it. It is not certified by any
independant body and not even legal to navigate with.

Ask them:http://www.c-map.com/default.asp

I see on their website that they have got some ISO approval for there
professional chart databases:

"The CM-93/3 and NT-Link databases consist of approximately 20,000
electronics charts with worldwide coverage, mostly used on ECDIS and ECS
on SOLAS-class ships, as an aid to navigation in addition to official
paper charts or ENCs. It is also widely used on naval vessels (in both
navigation and Command & Control systems) and Vessel Traffic Control
Centers."

Note the line "in addition to official paper charts or ENCs."

Don't be fooled. It is a lovely piece of eye candy, an aid, nothing more.

Gaz