Get the picture ……..

Over the last few years we have spent a fair bit on various electronic and paper charts, and like most cruisers have several charting software programs (Nimble Navigator and Open CPN) on several computers plus a Raymarine RL80C chartplotter. In our case our charts are CMAP 2010 except for the Raymarine which use CMAP NT+ . The latter generally has provided the best detail and accuracy because it seems to have more of the small scale charts embedded. However even this lacks detail when it comes to pilotage in and around reefs away from the commercial shipping areas and in some cases there can be significant datum offsets which need to be considered. (A good way to check this is to look at the chart source data and check if there is any Lat and Long offset versus WGS 84). Fiji is one of those places where a careful eye is needed on the electronic charts and because of the numerous reefs a lot of eyeballing and reading the colours of the water is required. While eyeballing with good light will always be necessary, sometimes at crucial moments the cloud comes over and in any case you need to have some pre planned idea of where to point the boat …. Wouldn't it be great if you could have a satellite picture of the reefs for the entrance to some of the bays to overlay on your charts? Well you can not only use Google maps this way, but you can make your own of any size and for free! So read on to see just how easy it is to make your very own Google charts. You can plan routes around reefs and rocks (which need to be monitored by eyeball) and you can overlay the ships GPS position and track on the map. It's very useful to do this on the Google map then flip over to the chart layer and see what it looks like. Often the correct route involves a “shortcut” over land! We started doing this in Fiji and have found it to be exceptionally accurate (usually more so than the chart) and generally a very clear and useful supplement to charts and eyeballs.

NB: You will also need a charting software program which can run ‘kap' charts. If you don't have one, there's a great high quality legal freebie called OpenCPN – many cruisers use this as their primary charting program. It runs CMAP (and others), does AIS and Gribs as well as many other features. You do need a good internet connection in order to download various programs and then to make your chart maps which are then permanently stored in your chart directory. So let's assume you have the connection – you need to download a few freebie software programs first:

    •  Google Earth

    •  GE2KAP (this is the program which makes the charts)

    •  ooRexx-4.1.0-windows-x86_32.exe (this is an interpreter for GE2KAP)

    •  OpenCPN charting software (if you haven't got a suitable program)

All of them can be found by searching on Google.

To continue:

    •  If necessary download and install OpenCPN charting software (the charts do not come with the program but we use     CMap charts)

    •  Download Google earth

    •  Download GE2KAP which comes as a zip file so download that and extract all the files. You will need a password "phiggins ” (Install to it's own directory not in program files)

    •  Download and install ooRexx – just follow all the instructions and take all the defaults.

    •  Open the directory where GE2KAP has been installed and you will see there is an icon GE2KAP.rex – this is the ‘exe' file to run the map making program. Send a shortcut of this on to the desktop.

OK you're almost there – just a few things to set up in Google earth:

Tools, Options: 3DView: choose: Texture Colours: True Colour; Anisotropic Filtering: Medium; Graphics Mode: DirectX; Check Compress

Lat/Long: Decimal Degrees; Unit of Measurement: System default

Terrain: Elevation exaggeration 0.01 Uncheck the Terrain quality

In View menu: Show Navigation bar – never.

In OpenCPN: Tools, Plugins and look for the GE2KAP plugin. If it's not there you must copy the file: ge2kap.pi.dll which you will find in the GE2KAP directory and copy it to the plugins folder in your OpenCPN program.

Right you're there now just need to make a chart and try it.

Open Google earth and look for an area you want to make a map for. Click on the icon you put on the desktop for the GE2KAP.rex – it will open a small panel (have a read of the instructions on the panel but don't panic because all you are going to do is to make a basic chart). The only thing you have to do is to enter a chart location name – NB: if you are using windows 7 you will need to put your charts into a folder under the c:\Users\.... (I use a folder for each country then just call the chart the name of the bay I'm making the chart for). Then click ‘ create chart' . You should get the message in the panel when it's done.

You now need to go into OpenCPN, Tools, Charts, Add directory and add the directory which contains your new chart. If you have put the chart into an existing directory which is already listed in OpenCPN then you will need to “Force full database rebuild”. You will then need to re-start OpenCPN. Once opened you should be able to see a red box outline around the area which has the Google chart. Just zoom in and you should have the satellite image. Get the picture?

 

Word of caution: We have found so far that the Google charts are accurate with the lat and long on the existing software but it's advisable to use them in conjunction with other charts. Disclaimer – these instructions are accurate to the best of my knowledge and are exactly the way I have done this – there may be other or simpler ways!

Below is an example of our track on a chart and map view of the south coast of Kadava in Fiji . Here the chart was not bad, but lacked detail and had us sailing on the reef. Some practice is occasionally needed to distinguish cloud from reefs, lower left.

South coast of Kadava – Fiji

 

 

 

 

 

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