ENC vs BSB charts

raisin56 · #1 (**permalink**) 11-12-2008

I recently installed openCPN navigation software as it supports ENC charts. I was thinking that vector based navigation would be much more accurate. What I found was that information on the raster charts was missing on the vector charts, namely any bridge information. Is this a function of the openCPN or is the information just not in the ENC files?

Thanks,
Dan

camaraderie · #2 (**permalink**) 11-13-2008

You have layers of information in an ENC file. I don't have your software but assuming you are looking at US charts...you may not have the right layers turned on...OR...you might not be at the right zoom level to see the bridge clearances. Play around a bit. For sure the info is there on US ENC charts.
I personaly like the BSB charts better but the ENC's do give you a lot of options.

raisin56 · #3 (**permalink**) 11-13-2008

Thanks Cam

I am using the NOAA charts for the Tampa Bay area. The software is a free open source product that lacks any documentation. I'll dig a little deeper, I thought I had all items displayed. I couldn't believe that the newer format would have less information, thanks for the confirmation that it should be there.

Dan

sailingdog · #4 (**permalink**) 11-13-2008

One of the problems is that unlike BSB charts, where the information is embedded in the chart image, the information for bridges and such in an ENC chart is a property of the vector shape and is stored in a separate table—and does not show graphically in many cases. The software generally has to support the information lookup and often will show it as a pop-up window or in some other way... but, generally the information isn't visible on the chart itself.

Basically, a BSB type chart is just a graphic image. An ENC chart is a series of databases, one of which is a vector description table that the program generates the visual chart itself from. If the sub-tables for the object information, like bridge height, isn't supported, there will be no way of looking it up.

raisin56 · #5 (**permalink**) 11-13-2008

Thanks SD

Cam nailed this one, the information is there. I just needed to zoom in further to find the right point on the bridge to click on to obtain the information.

Dan

camaraderie · #6 (**permalink**) 11-13-2008

Hey good! Even I get one right once in a while!

sailingdog · #7 (**permalink**) 11-13-2008

As I said...the info won't be "visible" on the chart... you had to click on the bridge to get the pop up with the information in it.

Quote:

Originally Posted by raisin56

Thanks SD

Cam nailed this one, the information is there. I just needed to zoom in further to find the right point on the bridge to click on to obtain the information.

Dan

jonlgauthier · #8 (**permalink**) 12-10-2008

Quote:

Originally Posted by sailingdog

As I said...the info won't be "visible" on the chart... you had to click on the bridge to get the pop up with the information in it.

Sailingdog,

The author of OpenCPN has a thread on Cruisers' Forum where a few members are helping beta test the software. Lot's of good info there.

sailingdog · #9 (**permalink**) 12-10-2008

Thanks, but the software isn't of much use to me, as I don't use a Windows-based system for my personal use. I use them enough for work, and refuse to use them for my own machines... and use a MacBook Pro instead.

Quote:

Originally Posted by jonlgauthier

Sailingdog,

The author of OpenCPN has a thread on Cruisers' Forum where a few members are helping beta test the software. Lot's of good info there.

floatsome · #10 (**permalink**) 12-11-2008

I think the following are "best practices" when using vector charts on small recreational cruisers:
1. Verify vector-chart plotted weighpoints and routes ahead of time during the planning phase using official paper charts and all other sources of information (rehearse).
2. Carry and reference official paper charts when navigating under way with electronic vector charts. Not all vector chart products carry the same information as official paper charts. It is easier to scan paper charts quickly for information than zoom and pan vector charts on small GPS chartplotter screens, less of a problem on laptops.
3. Routinely zoom up and down on the route ahead when navigating with vector electronic charts under way, since the data displayed changes at various zoom levels.

(Having popped up from my foxhole I now duck down to deke the flack.)