how to use downloadable charts?

[copacabana]

Is it possible to use free downloadable electronic charts with a GPS chartplotter? The Brazilian government offers all their charts of the coast of Brazil for free in vector and raster BSB formats:

If anyone is interested, the site is:

https://www.mar.mil.br/dhn/dhn/index.html

My question is this: how can I use these charts? I’d like to buy a new GPS chartplotter and be able to use the free charts (and not have to buy an expensive 3rd party cartridge loaded with Brazilian charts). Is it possible to download the charts and get them into a chartplotter? I’ve seen this done with laptops, but I’d rather not use a laptop for navigation. Also, if it is possible to do this, could someone please recommend a reasonably priced GPS chartplotter.

Thanks in advance!

[sailingdog]

You can't use them in most chart plotters. You can use them in laptops. Most chartplotters require that you download the proprietary charts offered for them. Nice to see that the USA isn't the only country offering nautical charts for free.

[copacabana]

Thanks for the reply Sailing Dog. Would you happen to know which chart plotters could use these free raster charts? I'm just trying to get a hold on this whole thing of electronic chartplotting and where the best value lies. I can buy a new GPS for about $500 and the chart kit for Brazil is over 1K USD. This is getting pretty expensive. I'm wondering if it isn't cheaper to buy a GPS tht can use the free charts. Or is there another alternative??? I'd rather not use a laptop for navigation, but if that's the easiest way to go ....

What are other people doing with these free charts?

[sailingdog]

I think the high-end Furuno NavNet systems were able to use the ENC format charts at one point, but I don't believe that is the case any longer.

[copacabana]

I guess that means I'm stuck with the chart kit cartridges or a laptop and USB GPS

The problem with using a laptop, as I understand it, is they don't last very long in the salt air (and are expensive) and require a inverter to run. When I add up all the costs I believe a new GPS and chart cartridge is probably the cheaper way to go. Still, it's a shame we can't get an off-the-shelf GPS chartplotter that can use the free charts ....

[Broomfondle]

I struggled with the Brazilian website a bit (I’m not good at languages) and found some BSB format raster charts to download. Couldn’t find any vector charts – which don’t mean they are not there – I just couldn’t find them.
The general trend these days is towards S57 vector charts. That said, I don’t actually know of any plotters that can use S57 directly. There are quite a few laptop applications around but I guess that is no help if a laptop is not for you.
btw – not all laptops would need an inverter but you would have to look around a bit.

[copacabana]

Broomfondle, I'm not sure there are vector charts, but they claim they offer them on the site. I haven't actually downloaded the charts yet. I'll have a look for the vector charts later and get back to you.

I can see from your site that you are the one to talk to about using these charts for laptop applications. It would be great if you could describe a typical setup for navigating with a laptop and what is involved.

Thanks.

[mitiempo]

I think you can get a 12 volt car type adaptor for any laptop. There are generic ones as well as those offered by the manufacturer of the laptop. It is more efficient than using an invertor.

[RXBOT]

Can you download to a SD card that a handheld GPS uses?

[Broomfondle]

The most basic setup consists of a just a laptop and a GPS. On the laptop you will need some charts and some software to display and work with them.
A wide range of laptops are suitable. I’d suggest a newer one which can readily handle any software and charts you throw at it. I’d also recommend the Windows 7 operating system which is much easier to use than any of its predecessors.
You’ll want to run the laptop off your main battery. There are quite a few 12v DC power adapters around (eg powerstream.com). These waste far less power than messing around with inverters. If your laptop manufacturer sells one then I would be inclined to choose that.
You need to connect the GPS to the laptop. NMEA 0183 is the usual communications protocol. Technically this uses RS422 (thats an electrical standard for serial data communications) which, with a bit of fiddling, can be made to work with the RS232 serial ports on older computers. But a modern laptop will only have USB (yet another serial comms protocol) so you need an adaptor. Easiest is to find a GPS which comes with a USB lead. If it comes with a serial lead then you will need an RS422 to USB convertor, preferably an isolated one which means there will be no direct electrical connection between your laptop and the GPS (eg kksystems.com). Either way you will probably need to install some software supplied with the adaptor.
Next thing, I’d say, is to think about the charts you want to use. We like free charts. Free charts make for safer seas. Unfortunately not every government has caught on to this yet. Raster charts often have better coverage and look better than vector charts but are less flexible and contain less information. Vector (S57) is where most chart producers, the national hydrographic offices, are going these days. Quite extensive portfolios of S57 are available from the likes of primar.org and ic-enc.org. These are aimed at commercial shipping, use an encryption method called S63, and can get a bit expensive. Proprietary charts are available through the likes of Transas, C-Map (now Jepperson) and Navionics. These can offer good value but because they are transcribed from the official government charts will tend to lag behind in terms of updates.
Having settled on the charts you may well find that the choice of software is then pretty limited. In general the more expensive software supports more chart formats and has more features. Basic functionality (position, routes) for the more common chart formats is available in several quite modestly priced software applications.